and House Use of the Sierra Tarascans (1944)
Ralph L. Beals, Pedro Carrasco, and Thomas McCorkle
ON MAIZE FROM CHERÁN
Missouri Botanical Garden and Washington University, St. Louis
|39 For laboratory space and many other courtesies, we are indebted to the Director. Dr. O. E. White.|
Fifty-five ears of maize were received from Dr. Ralph L. Beals, in lots numbered from 1 to 43, there being two ears each of most of the numbers above 30. The ears were photographed, grain samples were taken, and the ears returned to Dr. Beals. In the summer of 1912, 10 plants from each lot were grown at the Blandv Experimental Farm, of the University of Virginia,39 Boyce, Va. Although the planting as a whole was badly infested with smut, at least one good tassel specimen was obtained from each lot and herbarium specimens were also made of leaves and seedlings. Notes on plant color, pubescence, etc., were taken in the field, and the internode pattern of one plant of each lot was recorded. Five plants from the entire lot were investigated in detail, cytologically, and the knob number and knob positions of their chromosomes were determined.
As a whole, the corn belongs to the race recently termed "Mexican Pyramidal" by Anderson and Cutler (1942). Many of the ears and the plants grown from them are indistinguishable (for all practical purposes) from collections made in the vicinity of Mexico City. However, there are certain average differences which seem to be significant, and a few of the numbers are unlike anything we have yet examined from Mexico, D. F. Plants are medium to tall, mostly with conspicuous sun red (occasionally purple) plant color. Tillers are few or absent. The leaves are broad but break easily in the wind, giving the collection a very bedraggled appearance, which is heightened by the susceptibility to smut. The tassels are large and coarse but there are few tassel branches. The ears are short, though the husks are often very long. The ear branches vary greatly in length, the most extreme being 3 or 4 feet long, with numerous secondary ears. This is partly due to culture in a region of different day length (i.e., Virginia vs. Mexico). The ears are prevailingly broad at the base, tapering sharply and evenly. The kernels are mostly hard and flinty but are nearly all more or less dented. There is great variation in kernel size and shape, not only from plant to plant but also on each ear, since, owing to the position of the husks, the grains at the tip of the ear are under strong compression, whereas those at the base have plenty of room. It is not unusual to see an ear with the basal kernels deeply dented but with no perceptible denting in any of the kernels at the tip.
Two main types were well represented in the collections (table 18). There were the so-called "Black" maize from Cherán (Nos. 31-37) and from Nahuatzen (Nos. 38-43) and "Tulukénio" (Nos. 1-26), a mountain type grown only above 8,500 feet (pl. 8). A third type, "Trimásion," is grown on the plain below 8,500 feet. It is said to be later maturing, larger-eared, and larger-grained. This was apparently confirmed by our collections, but since there were only two numbers (29 and 30) no averages have been prepared.
The collections of Black maize stood out sharply both in the field and in the collection of ears. The latter were around 15 cm. in length, nearly all of them with dark (blue or purple) kernels which were deeply to lightly dented and were rounded (i.e., not pointed). Purple cob color was frequent, and many of the lighter cobs were flushed with purple or red. Many of the specimens belong to the color type called ''cherry" by geneticists. In the field the purple plant color of a good many of the plants was conspicuous as well as the almost complete absence of tillers, which were frequent enough in the Tulukénio collections to produce a mass effect and make the field look thicker below row No. 30 than it was above that number. A summary of the records shows that on the average the plants of Black maize were taller, that their leaves were a little less pubescent, and that they averaged 5 instead of 7 tassel branches. The differences between Black maize from Cherán and from Nahuatzen were minor, the chief one being more color in the seed coat itself in addition to the prevailingly dark aleurone color. On the whole, the plants from Cherán were a little more variable and were about what might have been expected if varieties from Nahuatzen were grown in close proximity to other varieties from Cherán.
While the Black maize of Cherán and Nahuatzen is in general very similar to Mexican Pyramidal corn from around Mexico City, its broadish, rounded grains, its less condensed tassels, and its tendency to purple plant color are atypical for that region.
Much of the Tulukénio maize is quite like the corn from Mexico City. Nearly all the ears had more or less pointed kernels (characteristically with a dent behind the point) and those which did not have them produced plants with pointed kernels. While there was great variation, most of the varieties were small-grained (7 mm. wide or less). Unlike the Black varieties (whose endosperm was invariably white) about half had yellow endosperm. While the Tulukénio maize varied greatly in the color of the grains, it was prevailingly light and much of it had a rather streaky, irregularly developed pinkish purple in the seed coat. The colored portions were not sharply defined as in variegated maize, but gave rather the effect of a colorless ear which had been lightly brushed with some such dye as eosin. It is apparently due to allelomorphs of the 'P' series. While a few of the ears were straight-rowed, on the whole they were very irregular, at least on a portion of the cob.
Three of the Tulukénio collections (Nos. 1, 9, and 12, table 18) were of particular interest since they are unlike any corn from Mexico City which we have so far examined and since resemblances to them were apparent in several other collections (e. g. Nos. 16 and 17). They are small-cobbed, very flinty, with no trace of denting, and the cobs cylindrical rather than tapering. That they are not merely poorly developed ears is proved by the fact that the plants grown from them were somewhat distinctive. They were short, one of them had more tillers than any other plant in the field, and their internode patterns revealed a strong tendency toward the Pima-Papago pattern rather than the Mexican Pyramidal pattern.
We do not yet have enough data about the kinds of maize to appraise the significance of these extreme variants of Tulukénio maize. It may he they are inferior types which have, through inbreeding, segregated out of better varieties. Since these mountain varieties are grown in isolated plots and since each family carefully preserves its own strain, this is quite likely. Even so, their morphology may be a significant throw-back to a type of corn once grown in this region, or in some region from which the Tarascan maize was derived. Since in most of their peculiarities they suggest Pima-Papago maize, which is known to be similar to the prehistoric Basket Maker maize (Anderson and Blanchard, 1942), it is possible that they are evidence of a primitive small-cobbed maize.
A cytological study was made of five different plants, by means of pachytene smears. Two of these plants had supernumerary or 'B' type chromosomes. The numbers and positions of the knobs on the 10 normal chromosomes are summarized in table 19. These facts will ultimately be significant when we have more data on knob numbers and positions from other types of maize (Mangelsdorf and Cameron, 1942). For the present we can say only that the knob numbers are intermediate between the high knob numbers of Western Mexico and the low numbers of the Mexico City-Toluca region.
TABLE 19.—Summary showing knob of each chromosome for 5 collections of maize from Cherán
|Chromosome No.||Knob number in collections of —|
|Tulukénio maize||Black maize||Average|
T = Terminal knob
The more significant measurements and observations made on the collection are summarized in table 18. Average values for the four most useful criteria of tassel morphology are shown graphically in figure 19, where they are compared with similar averages made on collections from pueblo-dwelling Indians in Arizona and New Mexico; from Pima, Papago, and allied tribes; and from Mexican Pyramidal varieties collected near Mexico City.
|FIGURE 19.—Average values for four characters of the male inflorescence (the tassel) of Beals' collections of Tulukénio maize and Black maize. Narrow lines show averages of other collections for comparison: Mex. Pyr., Mexican Pyramidal from Mexico City; P.-P., Pima-Papago; Pueblo (Carter, Anderson, Cutler collections). The four scales used from top to bottom are glume length in millimeters, tassel branch number '(values run from right to left for this scale), percentage of subsessile upper spiklets on tassel branches and percentage of condensed internodes on tassel branches.|
It will be seen that insofar as their tassels are concerned both the Tulukénio varieties and the Black maize varieties are intermediate between the Mexican Pyramidal and the Pima-Papago. On tassel morphology alone they are even closer to the latter than to the former. Since, so far as we can tell from the ears, Pima-Papago maize is very similar to that of the prehistoric Basket Makers (Anderson and Blanchard, 1942), this strengthens the suggestion made above that one element in the ancestry of this Tarascan maize may have been a primitive small-cobbed race somewhat like that of the Basket Makers. A diagram based on ear and kernel morphology would also demonstrate that both of these Tarascan types are intermediate between Mexican Pyramidal and Pima-Papago, but it would not indicate as close a resemblance to the latter as is given by the tassel morphology alone,
The maize varieties from two adjacent Tarascan villages are described and their characteristics are recorded in detail. While as a whole they are more or less similar to collections of Mexican Pyramidal maize from Mexico, D. F., they can be divided into at least three subraces. For two of these, the "Tulukénio" and the "Black" maize, there is enough material to define the central core of their variation. Black maize is grown in gardens below 8,500 feet. Characteristically it has large, dark, smoothly dented kernels on a tapering ear about 15 cm. long. While it has certain technical resemblances to Pima-Papago maize (low percentage of condensed internodes in tassel, length of glume, etc.,) it differs only slightly from Mexican Pyramidal. Tulukénio varieties are grown above 8,500 feet in small isolated plots in the mountains. They are even more like Pima-Papago; their tassels technically are closer to the latter than to Mexican Pyramidal. They vary greatly in color, size and shape, the largest ears being about the size of Black maize. The kernels tend to be small, more or less pointed, semidented; their seed coats lightly stained or streaked with red. The extreme variants of Tulukénio are small-cobbed, nontapering, early-seasoned, undented, and many-tillered varieties. They may possibly reflect a primitive small-cobbed race somewhat like the maize of the Basket Makers. If so, it was one element in the ancestry of Tarascan maize.
Taken in conjunction with Mangelsdorf and Cameron's recent (1942) analysis of knob number in Guatemalan maize, these results demonstrate the importance of considering altitude above sea level in interpreting the history and development of Zea mays.