Notes on the Origin, History, and Genetic Nature of the ... · Notes on the Origin, History, and Genetic Nature of the Cayenne Pineapple! J.1.COLLINS2 ALTHOUGH PLANTS AND FRUITS of

Notes on the Origin, History, and Genetic Natureof the Cayenne Pineapple!

J. 1. COLLINS2

ALTHOUGH PLANTS AND FRUITS of the pine­apple had been carried from America toEurope a number of times following their dis­covery by Columbus in 1493, it was almost100 years before they were successfully grownin Europe. They were first grown to fruitingin Holland about 1690 and in England some30 years later, following the development ofartificial heating of glasshouses.

Thereafter, a great rivalry and enthusiasmdeveloped in the growing of pineapples bythe gardeners of the large estates in Englandand on the continent. They imported varie­ties from America, exchanged varieties amongthemselves, and insome instances developednew varieties by growing the seeds which wereoccasionally found in their fruits or were ob­tained from the West Indies. As a conse­quence of this general interest in the growingof pineapples, the horticultural journals ofthe times frequently carried articles or noticesconcerning the culture of this fruit.

Like a number of important agriculturalcrops, the Cayenne variety of the pineapple,Ananas comosus (1.) Merr., appeared upon thehorticultural scene with no definite record ofthe manner or the place of its origin. The firstreference in the literature to the Cayennevariety appears to be the short notice carriedin the Gardeners' Chronicle (England) ofMarch6, 1841, under the column heading of "For­eign Correspondence," as follows:

IPubl ished with the approv al of the Director asMiscellaneous Paper No. 48 of the Pineapple ResearchInstitute of Hawaii, Honolulu, Hawaii. Manuscriptreceived August 23, 1950.

2Department of Genetics , Pineapple Research Ins ti­(Ute of Hawaii.

Paris, Feb. 4, 1841. As information is con­tinually demanded by horticulturists regard­ing pines, perhaps a few words as to thevarieties in request in Paris and the mode ofculture may not be unacceptable. The Pot­ager, or Royal Kitchen Garden Versailles hasthe merit of producing this and other fruits inthe greatest perfection. .. . The pinery con­sists of a vast number of pits , succession andfruiting houses, the whole of which are heatedwith hot water; it contains about 2000 plantsamong which are fine specimens of Queens ,Cayenne Lisse and Espineux , Black Jamaica.. . in all about 40 varieties. Only four kindsare considered desirable for general cultiva­tion; of these, however, more than 1000plants are annually fruited, namely 700Queens and 300 Cayennes, Endville, andProvidence. The Cayenne, both smooth andprickly, is of an excellent flavor and weighton the average from 9 to 12 pounds.

This article coritinues to record the namesof the three principal growers, or nurserymen,for the French market, one each in Paris,Versailles, and Meridon, who list Cayenneplants along with some other varieties.

From this date, 1841, we trace the historyof the Cayenne variety and map its distribu­tion in geography and time.

In this first reference to the Cayenne variety,mention is made of the smooth-leaved andspiny-leaved forms. Genetic studies in Ha­waii (Collins, 1936: 467) have shown that thesmooth-leaved type infrequently producesspiny leaves; if we can judge from this modernbehavior, then we can assume that the originalCayenne variety had smooth-edged leavesand also produced mutations giving rise tothe spiny-leaved form as bud sports.

[3 J

4

In the Gardeners' Chronicle for January 6,1844, we find another reference to Cayenne inthe section on "Notices to Correspondents,"as follows: "The Cayenne pine is from FrenchGuiana; cannot state its price, that is the af­fair of the nurseryman. .. ." A reader of thisjournal had obviously written to the editorinquiring about the place of origin of Cayenneand the price of plants, and the editor's replyindicates that it had been imported fromFrench Guiana.

In a description of the Cayenne variety in"The Pineapple Manual" (Anonymous, ca.1870), we find the statement that "This finevariety was imported from Cayenne manyyears ago and is now cultivated in manyplaces."

These scattered and brief references, to­gether with whatever weight may be givenbecause of the name it bears, point ratherclearly to Cayenne in French Guiana as theplace from which this variety was introducedinto France some time before 1840.

The fact that three French nurserymen in1841 had sufficient material to offer Cayenneplants in their catalogues indicates its pres­ence in France for a number of years previousto that date. In the "Pineapple Manual" men­tioned above; the statement is made that"Cayenne is not very free in producingsuckers ." At the present time we consider thathealthy plants will produce an average ofabout four reproductive shoots each in a 2..year growth period. The rate of increase froma small beginning would be .very slow andcould well require 15 or more years to pro­duce enough plants so that three nurserymencould offer them for sale. Accordingly we may .assume that a few plants may have reachedFrance around 1820 to 1825.

MIGRATIONS OF THE CAYENNE VARIETY

With the distribution of plants to nursery­men in France, Cayenne soon became afavored variety in Europe because of its large,well-shaped fruits , good color , and fine flavor,although the Queen variety was also widely

PACIFIC SCIENCE, Vol. V, January, 1951

grown and well received. The earlier distribu­tion of Cayenne to other countries appearsto have stemmed from England and not

. directly from France. This early 'distributionfrom England is also emphasized by its earlyappearance in some of the British colonies, ithaving reached Australia by 1858 and Jamaicain 1870, although it came to Jamaica viaFlorida. In Australia its development wasfairly rapid and from 1890 to 1895 that coun­try was able to furnish many slips and suckersfor expanding the pineapple industry in theHawaiian Islands, although the first Cayennescame to Hawaii from Florida in 1885 andJamaica in 1886.

The decade from 1885 to 1895 was a periodof accumulation of the Cayenne variety in theHawaiian Islands. Introductions of pineappleplants were made from 11 different tropicalcountries (Florida, England, Jamaica, Baha­mas, Trinidad, Puerto Rico , Mexico, Aus­tralia, Singapore, Samoa, and Algeria) four ofwhich were known to have included theCayenne variety. It is possible that it mayhave been included in shipments from othercountries as well, but the records do not listthe varieties in some importations (Collins,1934: 129).

Figure 1 shows two major centers of distri­bution of the Cayenne variety to other areas.England played this role during the last halfof the nineteenth century, although the firstEuropean propagation was accomplished in

.France. Hawaii has been a major source ofdistribution during the first half of the twen­tieth century. It was doubtless sent to stillother countries from these three major centersof distribution, but at present we do not havecomplete records. For instance, it was im­ported from Ceylon into South Africa, but wedo not know how it reached Ceylon.

THE ORIGIN OF CAYENNE

The discussion of the Cayenne variety upto this point is based upon documentary evi­dence. In trying to trace the origin of theCayenne pineapple beyond the realm of

The Cayenne Pineapple-CoLLINS 5

French GuianaDate?

ollandandelgium

1897

FranceH"'"5 plants B

about 1835-:England

-,· 1858

S

Philippines

/1863

/Azores

I1820

~

'"Oeylon

/ I1860 ca. 1895

/ - ~uthtAfricaFlorida

187b~ . ./ . 1885 Australia

Ja~ ~ ,)-893/

1886. -------- . , I_______ . Hawaii '~

194 . 1947~ ./

1926 1946 Cuba1923 1930 ~

Haiti \193\F'" Mexico

1)1

Formosa Africa(Kenya)

FIG. 1. Distribution of Cayenne following its introduction into France in 1820. Two major centers for dis-tribution appear: first England and then Hawai i, .

6

definitely known or documented history, cer­tain additional conclusions regarding its stillearlier history have been based upon circum­stantial evidence.

As has already been stated, some of theearly horticultural journals in England men ­tioned that the Cayenne variety had been im­ported from French Guiana. The name it bearsis also circumstantial evidence for that con­clusion. This latter statement is based uponthe frequency with which plants, particularlythe pineapple, are given names according tothe place from which the varieties are ob ­tained , even though they already possesslocal names. Among pineapples there are anumber of varieties named after geographicalareas in the West Indies and South America.Among these may be mentioned the follow­ing :

WEST INDIES SOUTH AMERICA

Antigua BahiaProvidence EsmeraldaJamllica 'PernambucoSt. Kitts TabogaCuban SurinamHavannah TrinidadPuerto Rico D emerara

In the hope that further knowledge regard­ing the history of the Cayenne variety mightbe found in French Guiana, a search was madeof the botanical literature for reports of plantsand plant collections in the northern part ofSouth America . This search disclosed the in­formation that in 1819 the French govern­ment sent an expedition to the French coloni­al possessions in America and the PacificOcean area to collect plants and seeds for theFrench botanical gardens at Paris and Ver­sailles. Samuel Perrottet, the botanist on thisexpedition, filed a report of the plants col­lected , in which he records finding a newvariety of pineapple growing at Cayenne, inFrench Guiana, having spineless leaves (theothers in the region having spin y leaves) anddelicately flavored fruits averaging about 20pounds in weight (Perrottet, 1825: 103).

He collected and sent to Versailles five

PACIFIC SCIENCE, Vol. V, January, 1951

plants of this variety in 1820. This date fits inwell with that which we have suggested aboveas being about the time the Cayenne varietyis presumed to have been introduced intoFrance.

The description, as it appeared in Perrot­ret's report, is included here as a part of thehistory of this variety, with a free translationfollowing it.

B romelia mai-pouri. Perro Cette nouvelleespece d'ananas provident de Cayenne; cinqplantes ont ete, comme je I'ai dit deposes aujardin des primeurs aVersailles. Le mai-pourin 'a point les feuilles arrnees de dents commeses congeneres ; ses fruits , d'un manger fortdelicat, pesent d' ordinaire 10 kilogrammes(20 livres), et sont tres-beaux. M.

This new species of Ananas was procuredfrom Cayenne; ' there were five plants as Ihave said, deposited in the garden of newvarieties at Versailles. The mai-pouri does nothave spiny leaves like its relatives; its fruits,of a very delicate flavor, weigh on an average10 kilograms (20 pounds) and are very fine.

The description given by Perrottet is in it­self not sufficient to establish the identity of" B romelia mai-pouri" and the Cayenne variety .In fact, the 20-pound average weight of fruitmentioned by Perrottet is difficult to believeof any variety of pineapple and must repre­sent an error in the record . The varieties Trini ­dad and Cabezona were reported to havefruits sometimes reaching 20 to 24 pounds,but there is no other reference to a varietyhaving an average fruit weight anywhere near20 pounds.

In commenting upon this description ofB romelia mai-pouri, Dr. 1. B. Smith , of theNational Museum in Washington, D. c., re­marked that it looked as if someone made amajor error between collection and publica­tion . An inquiry concerning these plants sentto the Natural History Museum in Paris re­sulted in information that no herbarium speci­mens now existed of this Mai Pouri variety,but that they were considered the same asSmooth Cayenne in 1850 by Gautier, "thefamous grower of Parisian pineapples ." The

The Cayenne Pineapple-CoLLINS

director of the museum stated that the dupli­cation of names had been published, al­though the term "Mai Pouri" remains an un­supported name.

The supporting evidence of the date of itsintroduction into France and the postulateddate based on the offering of plants for saleby nurserymen in 1841, together with thestatement that Gautier believed the two to beidentical in 1850, leads us to conclude thatthe five plants collected by Perrottet in 1820.represent the beginning of the Cayenne vari­ety in France.

How did this variety get started in FrenchGuiana? This question cannot :now and per­haps may never be answered with certainty.The collection of five slips sent to France in1820 we believe to be of the variety nowknown as Cayenne. Some time after it reached.France it was given the name it now bears.

The name used by the French botanist inhis report is somewhat confusing, since hecalls it a new species of Ananas, yet listed it asBromelia, a closely related genus in the pine­apple family. However, Perrottet probablyused the name given to him at the time hecollected . it. The name "Mai Pouri," bywhich this variety may have been known inFrench Guiana, probably followed the patternof indicating the place from which it origin­ated when it first appeared in French Guiana .The quest of the origin of the Cayenne wasthen continued in a search for a geographicalarea or locality having the name "Mai Pouri. "

In Colombia, at the junction of the Tri­parro River with the Orinoco River, is a smallvillage called "Maipures." In this region, andin the watershed of the Venturari River inVenezuela, also a tributary of the Orinoco,lived the Maipure tribe of Indians. We nowbelieve that the Cayenne pineapple originatedin the interior region of Venezuela long occu­pied by the Maipure tribe of Indians, and thatit was probably grown and used by them fora long period of time (Fig. 2) . Velez (1946 :427) , who recently traveled through the upperOrinoco River basin, states that the Piaroa

7

Indians have had under cultivation since timeimmemorial several pineapple varieties whichyield large, well-flavored fruits.

Another circumstance which may also havea connection with Maipure pineapple con­cerns the Esmeralda pineapple variety, grownin Mexico. This variety is very similar, if notidentical, to the Cayenne variety. Esmeraldasis the name of a small village at the mouth ofthe Esmeraldas River in northern Ecuador, inSouth America. The Maipure pineapplecould have been carried from Venezuela orColombia into the Esmeraldas region of Ecua­dor and thence into Mexico, where it wasgiven the name of the place from which it hadmost recently come. We have no indicationthat it was known as Maipure while beinggrown in Ecuador, but there is good evidencethat the Esmeralda and the Cayenne are thesame variety.

How long had this variety been grown inthe country of the Maipure Indians and whywas it not found by Europeans at an earlierdate? To the first question there is no definiteanswer. We suspect that the history of thisvariety may extend back into the antiquity ofAmerican civilizations along with such not­able plants its corn, tobacco ; and potatoes.

To the second question a logical answer isapparent. That area of South America is eventoday largely unexplored, partly because it haslong been inhabited by Indians who have hadlittle contact with outside people and becauseof the difficulty of travel in this little­frequented and still primitive area. TheMaipure Indians , who at one time roamedover this area, no longer exist as a distinctethnic group.

Sir Walter Raleigh, who conducted an ex­pedition in 1595 up the Orinoco River forabout 200 miles, reported having receivedquantities of pineapples from the Indians inthe deep interior of the country. The villageof Maipure on the Orinoco River is at theplace now marked on maps as the head ofnavigation. This is some 200 miles farther upthe Orinoco than the place reached by Ra-

s

leigh. Could Sir Walter Raleigh and his menhave been the first white men to find and eatthe Cayenne pineapple?

If the Cayenne pineapple originated in theMaipure Indian c,ountry, the parent variety orspecies 'may still be present as a part of thenative vegetation. Other members of the hy­brid population of which our Cayenne varietywas a member may still be among those usedby the Indians. Could some of the sibs of theCayenne variety be better fitted for large-scalecommercial 'production? Could some of thesibs have inherited resistance to diseaseswhich Cayenne failed to obtain? Could someof the sisters of Cayenne have inherited twoor more genes for yellow flesh color, whereCayenne obtained only one?

These are some of the questions which havebeen raised by this study of the origin of theCayenne variety of pineapple, to which an­swers should sometime be obtained.

VARIATIONS WITHIN THE CAYENNE VARIETY

Two types of hereditary variations, whichmay be designated as strain differences andmutations, exist within the variety.Strain differences

The term "strain" is used here to indicatehereditary differences in fruits or plants with­in a variety when the manner of origin ofthese differences is not known . A long timeago growers of this variety recognized straindifferences. The Journal of the J amaica Agri­cultural Society (about 1900) carried a state­ment that there was a good and a poor kindof Smooth Cayenne and that the latter wasalso known as the Honolulu kind!

Captain John Kidwell, an early pioneer ofthe pineapple industry in Hawaii, stated(Kidwell, 1904) that there were two distincttypes in Hawaii, and that he considered onemuch superior to the other. The poor type ofCayenne, according to his statement, hadbeen imported from Queensland, Australia,

PACIFIC SCIENCE, Vol. V, January, 1951

under the name of Smooth Cayenne. He de­scribed it as having a very large plant produc­ing fruits weighing from 7 to 15 pounds andnumerous slips on the peduncle beneath thefruit. The fruits, while of good quality, wereconical in shape and possessed a very largecore. The other type, which he called the"true" Cayenne, was similar in appeararice,but the plants were smaller and producedfruits from 5 to 7 pounds in weight. This typedid not produce slips on the peduncle be­neath the fruit. As a consequence of this lattercharacteristic, this good strain was necessarilypropagated from suckers and the crowns.

In 1887 a report of the United States De­partment of Agriculture on tropical and sub­tropical fruits mentions three kinds ofCayenne being grown in the Key West regionof Florida. These were listed as SmoothCayenne, Spine-leaved Cayenne, and Thomp­son 's Smooth Cayenne. No description of thethird kind was given, but its listing as aseparate strain indicates that it may have beendifferent in some respect from the others.

In Hawaii we recognize three strains ofCayenne, all of which produce good canningfruits but differ in some plant and fruit char­acters. The one used most extensivelythroughout the Islands is known simply asCayenne. The second strain, grown mostly onKauai , is known as the "Hilo" variety, or asthe Hilo Cayenne. 'The Hilo variety differsfrom Cayenne in at least three characters. Themost prominent difference is in the absence ofslips in the Hilo variety. It also produces asmaller plant and fruit, with the fruit morecylindrical and of better average quality. Itproduces more suckers than Cayenne and theplants have a darker green leaf color. Thesedifferences are about the same as those Cap­tain Kidwell used to distinguish betweenCayenne and what he called the Queensland

. type. The strain we now call Hilo appears to

FIG . 2. Location of the probable area of origin of the Cayenne pineapple, showing the location of the town of 'Maipures on the Or inoco River . The Venturari River (Ven. R .) area, for a long time the country of the MaipureIndians, is also :shown.

GOODE'SSERIES OF BASE MAPSWCNIn'I4.~lDI1OII

"'-'" '" H...., M.~N50J,M "' theU~ "'Chic.to '-Oic.tgo, IIIioooit

~,....... u--.JOoluIo

10 PACIFIC SCIENCE, Vol. V, January, 1951

TABLE 1CL ASSIFICATION OF SOMATIC M UTATIONS IN CAY EN N E

FRUIT MUTATIONS

I. Foliar proliferation of the fruitlet1. Crowning Beauty2. Hour Glass3. Slipping 'Beauty

II. Multiplication of floral organs4. Flowering Beauty (increase in pet al number)5. Multiple sepals and bracts

III. D isappearance of floral structures6. Dry fruit (only the floral bract subtending

the fruitlet remains)7. Bottle Neck (the upper one half to one third

of the fruit is like the dry fruit )IV. Changes in fruit characters '

S. Elongated bracts and sepals9. Big eyes

10. Slender11. Elongated fruit12. Self seedy13. R ough (pointed eyes)14. Non-porous flesh15. White flowers16. Nubbin (dwarf and abnormal frui t-eyes

small and distorted, surface very rou gh )M 226

be identical with the one Kidwell called the"true" Cayenne.

Our th ird strain is known as the Collar-of­Slips, because of the excessive number ofslips produced around the base of the fruit.It has a smaller fruit than the Hilo, is later inmaturing its plant and ratoon crops, and isgenerally considered an undesirable type.

These Cayenne strains have been present ascomponents of the variety for a long, long

FIG. 3. A plant of the Cayenne variety, showing slips,suckers , and a mature fruit.

PLANT MUTATIONS

V. Single character changes

17. Spiny leavesIS. Absence of anthocyanin19. Linear anthocyanin20. Blush anthocyanin21. Intensified anthocyanin22. Albino (no chlorophyll)23. Streaked anthocyanin24. Waxy (absence of trichomes)25. Semi-waxy (redu ction in trichomes)26. Me aly (increased trichome s)27. Few slips (573, M4W)2S. Increased number of slips (L69)

. 29. Multiple crowns30. Increased wilt tolerance (resistance)31. Increased chlorophyll (LHS)

VI. Multiple character changes

32. Paper Leaf (degenerate plant )33. B.B. (gigas form)34. Lanai (short leaf type)35. Driver's Dwarf (dwarf) .

time. How they originated or which repre­sents the true or original Cayenne cannot nowbe determined with certainty.

Figure 3 shows a typical Cayenne plant withslips, suckers, and a mature fruit .

M utationsThe term "mutation" is applied to new

hereditary variations which appear de novo in apopulation of plants or animals, caused by achange in the structure of a chromosome andthus in the hereditary constitution of the in­dividual.

Mutations have occurred in the Cayennevariety, giving rise to a series of new orchanged forms; some are so profoundlychanged that they no longer show the varietycharacters, others show only minute changes.

These mutan t forms are treated separatelyfrom the strains already discussed, principallybecause we know something about the originof these mutations and we do not know howthe strains originated. It is qu ite possible thatthe latter also started as somatic mutations.

The mutations in Cayenne can be con­veniently divided into six classes on the basis

The Cayenne Pineapple-COLLINS 11

In Lanai

increaseddecreasedsmallersame as normalsmallernormal

VARIATION FROM TYPICAL'CAYENNE

In B.B.

decreased .increasedlargerlaterlargermore

CHARACTER

Leaf number .Leaf length .Fruit size .Fruit matu rity .Plant size .Spines

represent profound genetic changes, eventhough the character alteration may be con­spicuous. The mutant Crowning Beauty (Fig.4) is an example of this kind of mutation.

Those in Class VI, however, stand apartfrom the rest because they represen t simul­taneous changes in a number of differentmorphological and physiological characters.

The Lanai type and B.B. mutations (Fig. 5)appear to be complementary to each other intheir deviation from the normal variety . Theyvary from typical Cayenne in opposite direc­tions in at least six characters, shown inTable 2.

TABLE 2CHARACTERS OF MUTANTS B.B. AN D LA NAI COMPARED

WI TH THOSE OF THE N ORMAL VARIETY

The Paper Leaf mutant departs so widelyfrom the normal variety in a number of char­acters that it no longer resembles the Cay- .

of the characters which are altered. Fourclasses affect the fruit and two classes affectboth fruit and plant characters (Table 1).

The mutations listed in the first five classesof Table 1 are relatively slight orsmall char­acter alterations. They influence one or a fewcharacters and do not, for the mos t part ,

~~ FIG. 4. A normal Cayenne fruit cut in longit udinalsection on the right, showing internal structures ofcore, carpels, and vascular fibers. On the left is themutant type Crowning Beauty , showing foliar pro­liferation of the fruitlets and absence 'of norm al carpelstructures.

FIG. 5. A norm al Cayenne plant in the center, with the short leaf Lanai mutation on the left and the long leafone on the right. These represent changes in opposite directions from the normal.

12

enne at all. It is considered a degenerate type,because of its small, worthless fruit and weak­ly growing plant. It probably could not sur- .vive in field competition with normal plants.

Driver's Dwarf (Fig. 6) has a diminutiveform of plant and fruit, combined with collarof slips and an intensified purple anthocyaninpigment in the leaves. This may represent achange from the normal slip type of the Cay­enne variety to the collar-of-slip strain. On theother hand, the mutation giving rise to dwarfand increased anthocyanin may have occurredin a collar-of-slip strain plant which was al­ready in the field.population. The dwarfingand anthocyanin intensification appear tohave been simultaneous changes.

FIG. 6. A normal Cayenne fruit on the left, with afruit of the mutant Driver's Dw arf on the right.

Discussion of'these more ob~ious mutanttypes naturally leads to the question of thepossible occurrence of other mutations whichare less conspicuous and less easily measured.Undoubtedly mutations of this kind takeplace, but the demon~tration of the existenceof mutations of slight phenotypic effect ismuch more difficult, because of overlappingvariations of a non-hereditary nature .

Some examples of these small or elusivemutant effects are briefly described to showthat at least a few are present in the variety.

PACIFIC SCIENCE, Vol. V, January, 1951

Two Cayenne clones were found to showa slightly darker green color, which could berecognized easily when a fairly large group ofthese were growing adjacent to a group of thenormal variety. A clone may be thought of asone plant multiplied many times by vegeta­tive reproduction, and all plants of a clonehave identical heredity. Chemical analyses ofleaves revealed a higher chlorophyll contentin these darker green leaves. A mutation ofslight effect on chlorophyll production wasprobably the origin of these darker greenclones.

The elongated fruit mutation listed inTable 1 develops a large number of multiplecrowns and fasciated fruits when grown inwarm, dry areas, but only normal plants ap­pear in the cool, more moist areas. In thiscase the additional character of multiplecrowns is quite obvious under one environ­mental condition and disappears (or mergesinto the normal pattern) when grown underother conditions.

The number of slips produced per plant isa character subject to considerable variation

.due to differences in the environment duringthe growth period. This is well illustrated bythe effect of relative crowding of plants in thefield. Close planting reduces the number ofslips, and, conversely, widely spaced plantspermit a larger number of slips to develop.Table 3 shows the variation in number of slipsresulting from an experimental planting ofCayenne with 10, 12, 14, and 16 inches be­tween plants (that is, with different degrees ofcrowding).

TABLE 3EFFECT OF DIFFERENT PLANT SPA CINGS ON SLIP

P RODUCTION

PLANT SPACING AVERAGE NUMBER

IN IN CH ES OF SLIPS

10 2.5112 3.3314 3.9516 .4 .36

Odds - 19 to 1 0.43Odds - 99 to 1. 0.60

Because of the susceptibility of this char­acter to variation due to environmental dif-

The Cayenne Pineapple--CoLLINs 13

CLONESA 1069 .0 7 - - - ( .49) - - 1. 0 8

B 666 . 15--(.58)--1.12

C L40 .19 --(.4 6) - -1.0 6

o L100 .3 8 --(.75)--1.21

E L62 .3 1---- (.90) - - - - 1.6 3

F 573 .7 3 - (.9 3)-1.2 0

G LH20 .7 4 ----(1.73)---- 2.12

H LH8 1.51 --(2 .07) - - 2.46

LHI4 1.54--- - (2 .32) ----- 3.10

3 .5

- - '--- 3.27

o

L69J

0.5 1.0 1.5 2 .0 2 .5 3 .0

MEAN NUMBER OF SLIPS PER PLANTFIG. 7. Ten Cayenne clones showing mean slip numbers for a period of 7 years, together with lowest and

highest yearly means.

ferences.vthe discovery of genetic variations(somatic mutations) which have an effect onslip number is more difficult than locatingmutations which are not subject to environ ­mental modification. However, by repeatedtests under similar environmental conditionsit has been possible to demonstrate the 'oc­currence of mutations affecting number ofslips in this variety.

Figure 7 shows the mean number of slipsper plant for 10 clones over a period of sevenplant crop harvests, together with lowest andhighest limits of the yearly means for thatperiod . Five of the clones had a range ofannual mean slip number which did not over­lap the range of three ' other clones. Twoclones, E and G, had a range of variationwhich overlapped all the other groups . Therecan be little doubt about a genetic differenceexisting between anyone ofthe three high slip­producing clones, H , I, ] , and anyone of thefive low-producing clones, A, B, C, D , and F.

The three high slip-producers, H, I, and],do not appear' to differ among themselves.Clone G, overlapping in its range with boththe high and low slip producers, appears to begenetically different from both groups.

These mutant clones can be compared witheach other, but should not be compared withthe mean of the variety, first because they area part of the variety and second because- thevariety being a mixture of genetic types­random samples would not always includethe same distribution of variant types.·Fur­thermore, most Cayenne populations includesome plants of the collar-of-slip strain , which

. produces a very high number of slips.

The somatic mu tations in Cayenne includea range of types varying from those having

"I'hese conclu sions are based upon another repli­cated plot test which showed significant differences aslisted here, and we presume that the causes of thedifferences were genetic.

14

marked, easily recognized characters to thosediffering so slightly that only statistical ana­lyses of quantitative data will identify them.

They are not frequent in occurrence, withthe exception ofa few which have been shownto be frequently mutating types (Collins,1936). The mutations discussed here havebeen collected over a period of 20 years ormore and from among millions of normalplants.

This variety is as stable genetically as arevegeratively propagated, highly heterozygousdiploid varieties in general. Were this nottrue, the variety could not have been main­tained through this long period oftime.

Cayenne is not the single clone it probablywas at the beginning. Now it is a collectionof clones, all having the same general char­acters but usually differing in one or a fewcharacters or degrees of expression of char­acters: The more obvious mutations and thosetoo poorly adapted to survive in the generalpopulation have been and are being reducedto small percentages or eliminated. The re­maining population heterozygosity consistsof minor character alterations which are car­ried along by asexual propagation in thegeneral mass of cultivated plants. As examplesof these latter clonal types, reference can bemade to some of those listed in Table 1, suchas the clone with less porous fruits, self­seedy types, low and high slip-producingforms, and increased amount of chlorophyll.

As to their value to the organism (in acultivated variety, positive value in horticul­ture) these somatic mutations follow theknown pattern of randomly occurring muta­tions; the great majority are either detrimentalor of no advantage to the organism. Onlythree of those which have been studied appearto have possible advantage in pineapple cul­ture, and only two of these, the wilt-resistantmutant and the high slip-producing type, areof possible importance.

TETRAPLOID CAYENNE

The pineapple normally has 50 chromo-

PACIFIC SCIENCE, Vol. V, January, 1951

somes in its somatic cells. This is consideredto be the diploid number for the genusAnanas. However, tetraploid Cayenne plantshaving 100 chromosomes were obtained aftertreating shoot growing points with colchicinesolution (Kerns and Collins, 1947). The im­mediate results from these treatments werevarious kinds of chimeras of diploid and tetra­ploid tissues, together with plants whicheither died early in growth or reverted to nor­mal diploid tissue throughout.

By careful selection of buds from the tetra­ploid sectors of chimeras during several suc­cessive vegetative generations, constant newtypes which fall into the following threeclasses on the basis of the amount and loca­tion of tetraploid tissue were obtained.

Class 1 was completely tetraploid.Class 2 was tetraploid except for a diploid

epidermis.Class 3 was diploid except for a tetraploid

epidermis.Classes 1 and 2 were alike in all visible

characters. Class 3 was like the normal diploidin all visible characters.

The tetraploid has been compared in Table4 with the diploid in a number of importantcharacters. The fruit weight is less in the tetra­ploid and the fruit has fewer eyes than in thediploid. The average eye weight, however, ishigher in the tetraploid, showing that theindividual eyes of the tetraploid are larger.The Brix (dissolved solids including sugars)of the tetraploid fruit is lower than in thediploid fruit . The characters of fruit acidity,translucence, and vitamin C content are high­ly variable, so that no significant differenceswere obtained. These characters are readilyaltered by different environmental conditions.

Tetraploid plants are taller than diploids,but they have fewer leaves and produce fewerslips.They do not differ in average leaflength,although the tetraploids have wider leaves.The tetraploids also have a higher percentageof water in the leaves and, as a consequence,a lower percentage of dry matter per unitweight of green leaf tissue.

.I

The Cayenne Pineapple-CoLLINS 15

In many plants, and particularly in orna­mentals, valuable horticultural characters areobtained by doubling of the chromosomes(Emsweller, 1948: 570). However, the tetra­ploid Cayenne is inferior to the diploid formin several important characters (Table 4).

GENETIC NATURE OF CAYENNE

The Cayenne pineapple normally has seed­less fruits, although it does produce normalgerm cells. The seedlessness results from acondition known as self-incompatibility.Under these conditions the germ, or sex, cellsof the same individual do not unite in ferti­lization to form embryos. Germ cells fromtwo different varieties, Cayenne and Queen,for instance, are mutually compatible and

The fruits are seedless, as are the diploids.The chromosomes perform regularly in germ­cell formation, and functional gametes areproduced.

Crosses between the Cayenne tetraploidand varietal hybrid tetraploids produce viableseed readily, but crossing with diploid formsproduces very little seed; this is similar to theresults obtained when varietal hybrid tetra­ploids are crossed with diploids.

TABLE 4COMPARISON OF THE FRUIT AND PLANT CHARACTERS

IN THE DIPLOID AND TETRAPLOID CAYENNE

CHARACTERS

Fruit weight (lbs.) .Eye number .Eye weighr (gm.) .Brix .Acidity (per cent) .Vitamin c. .Translucence .Plant height (cm.) .Number of active leaves .Leaf length (cm.) .Leaf width (cm.) .Percentage water in leavesPercentage dry matter inleaves , .

Pollen grain diameter (mi-crons) .

Stomata size (microns) .

"Significant differences.

DIPLOID

5.8140.416.315.40.71

19.22.7

28.157.665.0

5.481.8

18.2

47.022.0

T ET RAPLOID

4.0*105.6*16.8*13.8*

0.8620.8

2.330.5*44.2 *65 .2

6.2 *83 .5*

16.5*

64 .0*31.0*

seeds are produced following cross pollinationbetween the varieties.

Inasmuch as inbreeding is thus denied be­cause of self-incompatibility, the studies ofthe genetic nature of Cayenne have been con­ducted largely from the results of varietalcrossings and from examination of the soma­tic mutations which have appeared in fieldpopulations.

Cayenne has a diploid number of 50 chro­mosomes; in the somatic cells they appearslightly elongated or almond -shaped (Collinsand Kerns , 1931: 140); in the germ cells, theyare almost round. While the process of germ-

. cell production is usually normal, some ab­normalities occur. The most frequent ab­normality is the formations of germ cellscontaining 50 chromosomes, which is doublethe ordinary number of chromosomes ingametes. These appear in the mature sex cellsas giant pollen grains and ovules.

In crosses between Cayenne and othervarieties, these giant germ cells .give rise tooccasional hybrids having 75 or 100 chromo­somes instead of the normal number of 50for this species.

The number of these plants whose cellshave 75 and 100 chromosomes is far belowthe expected number on the basis of the per­centage .of 50-chromosome germ cells pro­duced. This shows that only a small propor­tion of the plant gametes function in ferti­lization and that selective fertilization in favorof the normal 25-chromosome gametes takesplace.

Hybrid populations resulting from crossingCayenne with other varieties provide someinformation regarding the genotype or heredi­tary constitution of the Cayenne variety.

The variety is heterozygous for many reces­sive and dominant genes. Table 5 gives someinformation on the genotype of Cayenne ob­tained from crossing with other varieties.

INBREEDING IN CAYENNE

In discussing the somatic mutations whichhave appeared, mention was made of the self-

16 PACIFIC SCIENCE, Vol. V, January, 1951

TABLE 5

THE GENOTYPE OF CAYENNE WITH RESPECT TO CERTAIN CHARACTERS

CAYENNE CONTRASTING CAYENNE CAYENNE DOMINANCECHARACTER CHARACTER GENOTYPE RELATION

Spiny tip leaves spiny leaves Ss dominantSpiny tip leaves piping leaves pp recessiveAnthocyanin in leaves no anthocyanin Aa intermediateYeIIow flesh white flesh Yy int erm ediatePurple petals white petals WW dominantChlorophyll no chlorophyll Cc dominantNormal fru it proliferation * recessiveSeedless seedy * recessiveLong leaves short leaves * dominant

*Underermined.

populations supply some evidence regardingthe parentage of Cayenne itself. The origin ofthis variety as a hybrid between any of theknown species of Ananas can be ruled out,we believe. The parent or parents producingthis variety through sexual reproduction mustbe considered at present as unknown varietiesof A . comosus, or of such a variety of A .comosus and a species of pineapple not knownat the present time.

SUMMARY

The Cayenne variety of pineapple was first. mentioned in an English horticultural journal

in 1841. Evidence is presented to show thatit came from French Guiana in 1820. It ispresumed to have been grown by the MaipureIndians in the upper Orinoco River valleylong before it reached French Guiana. Themanner and time of its origin are obscure.

After its introduction into France and Eng­land, it became established in many tropicalcountries during the 100 years between 1840and 1940.

The genotype of the variety is highlyheterozygous and it exhibits hybrid vigor inits growth. The variety is self-incompatibleand must be propagated vegetatively. Duringits long period of vegetative propagation anumber of somatic mutations have appeared,including one giving the mutant type self­compatibility. The present Cayenne is a mis­cellaneous collection of clones. The diploidchromosome number is 50, with 100-chro-

fertile mutation. In this form, the self­incompatibility characteristic of Cayenne isreplaced by self-fertility asa result of a domi­nant mutation, but in all other respects thevariety characters remain unchanged.

Inbreeding can now be carried out in thevariety by using these self-fertile mutants.Inbreeding is a potent tool for dragging re­cessive skeletons out of hereditary closets anddisplaying them in the light of day for all to .see. By the use of this tool we have pried outof Cayenne recessive secrets which it has longcarried buried within its genotype.

About one fourth of the inbred progenyare semi-lethal and die in an early seedlingstage. Another fourth are so weak that theygrow very slowly and reach fruiting maturitylong after the parent Cayenne. Most of theinbreds are low in vigor, with only a few ap­proaching that of the Cayenne variety. Theyexhibit a wide variation in fruit and planttypes, including many fruit and crown fascia­tions . The inbred population supplies evi­dence that Cayenne is not only heterozygousfor many recessive and some dominant char­acters, but that it exhibits heterosis or hybridvigor.

A number of variations which had appearedin the variety as somatic mutations also ap­pear in the inbred population in numbers in­dicating Mendelian segregation in a hetero­zygous genotype.

The general characteristics of the . inbred

·The Cayenne Pineapple-CoLLINS

mosome terraploids obtained by treatment ofdiploids with colchicine. The tetraploidsareinferior to the diploids.

REFERENCES

ANONYMOUS. Ca. 1870. The pineapple man­ual, being a guide to the successful cultiva­tion of the fruit and construction andmanagement of the pinery by contributorsto the Journal of Horticulture. London:Jour. Hort. and College Gardener.

,COLLINS, J. 1. 1934. Introduction of pine­

apple plants into Hawaii and some briefaccounts of pioneer pineapple growing.Pineapple Quart. 4: 119-120.

--- 1936. A frequently mutating gene inthe pineapple, Ananas camosus (1.) Merr.Amer. Nat. 70:467-476.

- -- and KENNETH R. KERNS. 1931;Genetic studies of the pineapple. 1. A pre­liminary report upon the chromosomenumber and meiosis in seven pineapple

17

vaneties (A nanas sativus Lindl. ) and Bro­melia Pinguin 1. Jour. Hered. 22: 139-142.

EMSWELLER, S. 1. 1948. Breeding of orna­mental plants. Amer. Soc. Hort. Sci., Proc.51: 565-574.

KERNS, K. R. , and J. 1. COLLINS. 1947.Chimeras in the pineapple. Jour. Hered.38 :323-330.

KIDWELL, CAPT. JOHN. 1904. The cultivationof pineapples in Hawaii. Hawaii. Foresterand Agr. 1 (12).

PERROTTET, SAMUEL. 1825. Catalogue rais­sonne des plantes introduires don lescolonies francaise de Mascareigne et deCayenne, et de celles rapportees vivantesdes mers d'Asie et de la Guyaneau Jardindes Plantes de Paris. M em. Soc. Linn. 3(3):89-151.

VELEZ, ISHMAEL. 1946. Wild pineapples mVenezuela. Science 104: 427-428.