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Races of Maize in Cuba (1957)

Chapter: 'METHODS OF COLLECTION AND CLASSIFICATION'

« Previous: 'HISTORY OF CUBAN CORN'
Suggested Citation:"'METHODS OF COLLECTION AND CLASSIFICATION'." National Research Council. 1957. Races of Maize in Cuba. Washington, DC: The National Academies Press. doi: 10.17226/21253.
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Suggested Citation:"'METHODS OF COLLECTION AND CLASSIFICATION'." National Research Council. 1957. Races of Maize in Cuba. Washington, DC: The National Academies Press. doi: 10.17226/21253.
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Suggested Citation:"'METHODS OF COLLECTION AND CLASSIFICATION'." National Research Council. 1957. Races of Maize in Cuba. Washington, DC: The National Academies Press. doi: 10.17226/21253.
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Suggested Citation:"'METHODS OF COLLECTION AND CLASSIFICATION'." National Research Council. 1957. Races of Maize in Cuba. Washington, DC: The National Academies Press. doi: 10.17226/21253.
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Suggested Citation:"'METHODS OF COLLECTION AND CLASSIFICATION'." National Research Council. 1957. Races of Maize in Cuba. Washington, DC: The National Academies Press. doi: 10.17226/21253.
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Suggested Citation:"'METHODS OF COLLECTION AND CLASSIFICATION'." National Research Council. 1957. Races of Maize in Cuba. Washington, DC: The National Academies Press. doi: 10.17226/21253.
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Suggested Citation:"'METHODS OF COLLECTION AND CLASSIFICATION'." National Research Council. 1957. Races of Maize in Cuba. Washington, DC: The National Academies Press. doi: 10.17226/21253.
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HISTORY OF CUBAN CORN 11 of any race of Caribbean maize, is adequate proof of the existence of corn on Hispaniola in the early sixteenth century, and thus tends to confirm Las Casas' version of Columbus' Journal. We may assume that what Oviedo said of Hispaniola can be applied directly to Cuba, for he wrote (Lib. XVII, Cap. IV) that the natives of Cuba lived just like those of Hispaniola, that their agriculture was of the same type, and that they possessed all the cultivated plants, fruits, and vegetables known on His- paniola. Las Casas ( Apologetica Historia, Cap. XI, XX) briefly described Hispaniolan maize. He stated that each plant commonly pro- duced three ears, each of which contained six hundred to eight hundred grains, and that purple, red, white, and yellow grains sometimes occurred in a single ear. The first direct post-Columbian reference to maize in Cuba appears to be that of Antonio Vasquez de Espinosa ( 43), a Carmelite friar who returned to Spain from a trip to the New World in 1622. He reported that Santiago de Cuba and Habana were provided with an abundance of meat, maize, manioc, and seafood. Three nineteenth-century Cuban writers on agricultural sub- jects, La Sagra ( 29), Bach iller y Morales ( 4), and Reynoso ( 36, 37), described the importance of maize in Cuba's economy and offered opinions about contemporary cultural practices. Reynoso proposed a study of "the different varieties of maize," but appar- ently never completed this work. Kuleshov ( 26) wrote that the small collections of Cuban corn he received from Bukasov were very uniform compared with those from other Latin American countries. He stated that they were of the indurata type and were similar to the maize ofSpain, Italy, and Argentina. Del Valle (15, 16) distinguished two types of Cuban corn, a dent called "Gibara" and a flint he named "Habana." In trying to separate by inbreeding the "different types of corn which enter into the mixture called Mafz Criollo," he obtained a few floury grains, from which he readily developed a true-breeding Hour corn. Del Valle later reported the production of a sweet corn adapted to Cuba ( 17), a commercial hybrid (18) and, with E.

12 RACES OF MAIZE Hidalgo Gato, a popcorn ( 19). Another Cuban corn-breeder, Manuel Diaz Cuevas, produced by continued selection in the 1940's an improved form of "Maiz Criollo" which he called "Victoria." Hernandez ( 24) briefly described six races of corn in Cuba and stated that five of these were probably related to Mexican varieties. Brown ( 8) gave detailed descriptions of the five races of maize which he found in Cuba and stated that their relationships were predominantly with South America, although he considered that the Cuban cylindrical dents probably could be traced to Mexico. METHODS OF COLLECTION AND CLASSIFICATION CONCEPT OF RACE In many recent studies of types of maize, concept of race has been based on a definition proposed by Anderson and Cutler ( 3): "a group of related individuals with enough characteristics in common to permit their recognition as a group." In spite of its redundancies, this definition has the merit of emphasizing the necessity of employing several characters. The authors further state that such characters should not be trivial but rather should be those which reflect the interaction of a large number of genes. The definition, being chiefly morphological, corresponds well with conservative taxonomic practice while emphasizing at the same time certain contributions of maize genetics. An immediate difficulty, perhaps not fully appreciated by An- derson and Cutler, is that it is possible to select from granary piles ears with a large number of characteristics in common which are sufficiently different from most other ears to permit their recognition as a group. Such practices need not be fraudulent; indeed, the collector may find it quite impossible to determine whether he is dealing with relatively pure types of a somewhat rare race or simply a segregating type which has happened to have caught his eye. Hernandez, for example, described a yellow popcorn as a race of Cuban maize on the basis of ears selected from four granary piles for likeness to the Mexican Nal-tel race.

COLLECTION AND CLASSIFICATION 13 Subsequent attempts to find plantings of this race have yielded negative results. The Anderson-Cutler definition leads to a second, less obvious difficulty - that of distinguishing between a common mongrel or mixed type and a well established race. In an area like eastern Cuba, where two or more well defined, true-breeding races have recently been thrown into contact, mixing of germ- plasm is common, and in granary piles mongrels are sometimes more abundant than relatively pure types. Such mixtures often have enough features in common to permit their recognition as a group. Indeed, Brown described as a race of Cuban maize a common and persistent type which he stated was intermediate between, and probably a hybrid derivative of, two other well defined races. Yet it would seem to be the feeling of most students of maize that well defined races of some antiquity should be distinguished from mongrel types which, although admittedly potential or incipient races, have existed for only a few genera- tions. Chance segregates and recent mixtures can be eliminated from consideration by slight modifications of the definition of Anderson and Cutler. Such modifications clarify but do not alter the concept of race. Since a race consists of one or more groups of living organisms, it would appear desirable in the case of maize to demonstrate the existence of interbreeding populations of plants having certain characteristics in common. Such a provision auto- matically eliminates the possibility of describing a group of chance segregates as a race. Mongrels may be detected best by inbreeding and observation of degree of segregation in the F 1 generation. A useful supplement to such studies is the careful determination of local names for races. In Cuba and probably elsewhere, well established races have names which may vary from region to region but are usually stable within a relatively large area. Mongrel types, on the other hand, are usually not named or are recognized as mixtures or "degenerations." In fact, planters who have idealized concepts of how their variety should appear are not uncommon, and such concepts usually differ little from the investigator's notion of the pure form of the race, obtained from observation of many collections. Such considera-

14 RACES OF MAIZE tions lead to the definition of race of maize as a group of one or more populations of true-breeding individuals with a number of significant characteristics in common. Implicit in the definition and helpful in identifying the races of maize in any country is the fact that such a population is usually recognized as an agri- cultural variety by the more careful farmers among the people who grow it. PRELIMINARY CLASSIFICATION In Februarv 1949, E. Hernandez X. and I. D. Clement made an " extensive collection of Cuban corn. Seed from this collection was used in a vield test conducted at the Atkins Garden in the summer of 1949. About 400 of the resulting ears, which represented a sample of the major variation in Cuban commercial corn, were stored in metal containers. In 1953 the present writer found that if these ears were arranged in a line according to the relative amount of soft starch appearing at the apex of the kernel, the variation was continuous. If the ears were simultaneously arranged in order of increasing width of grain, one end of the previous linear arrangement was split, so that the collection now lay in the form of a Y. The three extreme types were (a) flints of intermediate grain width; (b) wide- grained dents; (c) dents with very narrow grains, almost isodia- metric in cross section. Surprisingly, other characteristics were correlated. Thus, the narrow-grained dents had long, slender, flexible cobs and soft glumes. The three extreme forms corres- ponded well with the three races already described by Hernandez ( 24) and later also by Brown ( 8) and suggested the hypothesis that most Cuban corn consisted of three main types, together with their hybrids and recombination products. In fact, if this sample fairly represented Cuban corn, it appeared that relatively pure races must be uncommon in Cuba and that the country must swarm with mongrels. COLLECTIONS IN 1953 This impression was confirmed on a brief field trip to Oriente province in 1953. In commercial granaries and on farms the proportions of pure flint, pure dent, and intermediate semiflint

COLLECTION AND CLASSIFICATION 15 types were approximately the same as those observed in the yield test obtained from the Hernandez-Clement collection. Grain dealers and growers of this major corn-producing region of Cuba repeatedly offered the opinion that "degeneration" of well known varieties was an increasingly serious problem. Relatively pure forms of the commercially important orange flint corn called "Argentino" were said to be scarce, although similar types with a somewhat higher proportion of soft starch in the endosperm were abundant. Many dealers strongly believed that the modern Cuban grower was becoming more and more careless in his farm- ing methods. A somewhat more easily demonstrable cause for "degeneration" of Cuban varieties of maize would appear to be the recent rapid destruction of physical isolating factors which formerly prevented large-scale hybridization of races. A wide two-lane concrete high- way, constructed in the early 1930's, extends from the city of Pinar del Rio, in western Cuba, through Habana to Santiago de Cuba, a distance of 1143 kilometers. Hard-surface roads, rail- roads, and airlines provide ready access to all major cities and towns not on the Central Highway. Converted military vehicles provide regular bus service over rough secondary roads during the dry season. Where jeep roads stop, mule trains carry supplies to coffee farms. Markets in the principal cities sell food carried by rail or truck from all parts of Cuba. Modern tractor-trailers heavily loaded with cooking bananas from Oriente are a common sight anywhere along the Central Highway. Market vendors buy shelled Oriente corn in 100-pound sacks and sell it by the pound to housewives. Such corn, of course, is frequently tested by local growers. One farmer in Naranjo, a town in the Trinidad Moun- tains four hours by jeep from Cienfuegos, was found in possession of an ear of the Tuson race, until recently restricted to Oriente province, about 500 kilometers distant. He stated that he had bought his seed corn in the Cienfuegos market, whence it had come by truck from Oriente. Nevertheless, since it seemed possible that relatively uncon- taminated forms of the major races might still be found in some of the more inaccessible parts of Cuba, an intensive search for

16 RACES OF MAIZE types similar to the extreme forms found in the progeny of the Herm1ndez-Clement collection was undertaken in the moun- tainous regions of Oriente province. The results of this excursion were not entirely negative. Farmers shown specimens of extreme forms of the Tus6n, Canilla, Argentino, and pop types often were able to give the names and addresses of people believed to grow those varieties; usually it was possible to locate such individuals and actually to collect suitable specimens. An unexpected result of the trip, however, was the discovery that the people living in relatively remote parts of Cuba were mostly recent immigrants to such areas. Many were "precaristas" (squatters) who had moved from rude huts along government roads on the outskirts of towns to new lands in the mountains opened by lumbering operations which had partially destroyed the virgin native forests. In such cases they often obtained their seed corn in the villages from which they came. It is the writer's experience that intensive searches among these unfortunate people for remnants of pure races of corn are not likely to be fruitful. Much better success in obtaining relatively pure types was had in the more prosperous corn-growing districts with good access to important centers of commerce. In such places, by in- specting the condition of the house, yard, and fields it was possible to guess with some accuracy the degree of mongrelization of a man's corn. If the field was free of weeds and the house freshly thatched, the owner generally was found to take special pains to maintain the uniformity of his corn and to select his seed carefully for the type he preferred. Such successful farmers tend to in- crease their holdings by purchasing the property of their less industrious neighbors. Their cornfields increase in size with the years, and the importance of contamination from pollen of corn grown by neighbors decreases. Thus by continued careful selec- tion and growth, the successful Cuban farmer improves the uni- formity of his corn. Relatively pure forms of three races were collected on such farms. CHARACTERS USED IN CLASSIFICATION Since Cuban corn collected on farms and in commercial gran- aries is often of mixed parentage, measurements of plant and

COLLECTION AND CLASSIFICATION 17 tassel characters were made only on collections which bred true (in a relative sense) in experimental plantings. Two crops planted at the Atkins Garden in the summer of 1953 and the winter of 1953-54 were thus devoted to elimination of mixtures and testing of crosses and inbred lines which, it was hoped, might aid the determination of origins of certain races. Several stocks were obtained which bred true to type, although the number of collec- tions represented was much reduced. In the summer of 1954 vegetative characters were measured in seventy-seven stocks in seven races. Excellent growing condi- tions, characterized by long hot days with frequent heavy after- noon showers, resulted in a vigorous crop. Eliminated were all data obtained during the growing season from stocks which at harvest were found to have produced ears not characteristic of the race to which they had been assigned. Despite these precautions, the differences in vegetative charac- ters were slight among the four races of Cuban maize important in commerce. Average plant heights; for example, varied only from 2.58 to 2.64 meters, and internode patterns were scarcely distinguishable. Although with considerable field experience it is possible to recognize certain Cuban races by glossiness, color, or shape of leaf or by degree to which tassel branches droop, such characteristics are difficult to measure or describe and are of doubtful biological importance. Indeed, perhaps the most strik- ing feature of Cuban maize is that plants which are essentially identical in most respects produce ears which are very distinctive. Such observations lead naturally to the hypothesis, discussed in detail below, that the races of Cuban maize have undergone re- peated hybridization and selection. Since the latter operates only on the ear (except insofar as certain vegetative characters may be correlated with those of that structure), the features which distinguish the common races of Cuban maize are most apparent in the ear. Characters of the ear were studied in specimens selected from a collection of 991 ears obtained in 1954 and 1955 at seventy-one farms and six commercial granaries. In cases in which material collected in the field was insufficient, as in the pop and white dent races, ears grown at Soledad were studied. Since the high degree

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