Corn Races Research Articles

Ecological niche models of productive corn races under climate change scenarios in central‐eastern Mexico

AbstractCorn (Zea mays L.) is the basis of the Mexican diet. In this country, corn is produced by about 2.5 million small farmers and grown on 8.4 million hectares in rainfed agriculture. However, its production is not enough to meet demand. Climate change may negatively impact corn production, putting Mexico's food security at risk. The main goal of this work was to identify which corn races can find favorable environmental conditions in the future under climate change scenarios in the Sierra Madre Oriental. The Sierra Madre is a region highly vulnerable to climate change; in 2020, corn production was 5,785,561 Mg yr−1 of which 49.87% was from rainfed agriculture. These corn races could be proposed to replace others not tolerant to climate change, mainly at high altitudes. Potential distribution models were obtained for seven highly productive maize races. The projections were generated with the MaxLike algorithm using representative concentration pathways 4.5 and 8.5 scenarios to 2050 and 2070. In addition, general circulation models (CCSM4, GISS.E2‐R, and MPI‐ESM‐LR) were used. Our results show that the Tabloncillo and Tuxpeño races could slightly increase their potential distribution in the future. Both corn races present the highest number of municipalities with adequate environmental conditions for their future presence. As a strategy for adaptation to climate change, it is proposed to replace or complement maize races in high‐altitude areas with other tropical ones with greater tolerance to high temperatures, such as the Tuxpeño race.

Evaluation of Resistance of Eleven Maize Races (Zea mays L.) to the Red Spider Mite (Tetranychus merganser, Boudreaux).

At least 59 maize races (Zea mays L.) have been registered in Mexico. The feeding damage caused by insects and mites to maize crops generates up to ~30% of maize yield losses. Spider-mite-resistant plants are needed. The red spider mite, Tetranychus merganser Boudreaux (Acari: Tetranychidae), is distributed in the United States, China, Mexico, and Thailand. It is considered a potential pest in Mexican agriculture. The aim of this study was to evaluate the resistance mechanisms (antixenosis and antibiosis) of 11 native maize populations, representative of each race of maize grown in Tamaulipas, Mexico, to T. merganser under laboratory conditions. The aim was also to obtain information on the chemical composition and some morphological characteristics of these maize races and to identify resistant maize races for incorporation into a breeding program. Antixenosis was assessed by non-preference for oviposition and feeding. Antibiosis was measured by growth rate (ri). The presence of secondary metabolites in the 11 maize races were different. In the 11 maize races, quantitative analysis of total phenol concentration, total flavonoid concentration, and antioxidant capacity were significantly different. The multivariate analysis of variance showed that there is evidence of antixenosis noted by maize race differences in egg laying and percentage feeding damage but not of antibiosis noted by growth rate. Red spider mites laid significantly more eggs on the Celaya (24 h: 25.67 ± 17.04, 48 h: 42.67 ± 26.86, 72 h: 49.33 ± 28.54) race than on Raton (24 h: 7.00 ± 5.00, 48 h: 12.67 ± 8.02, 72 h: 14.67 ± 9.29) and Elotes Occidentales × Tuxpeño (24 h: 9.67 ± 5.85, 48 h: 15.33 ± 10.69, 72 h: 17.67 ± 10.97) races. However, the growth rate and mortality of T. merganser in the 11 corn races were similar. The Vandeño (24 h: 11.67 ± 2.89, 48 h: 27.67 ± 7.64, 72 h: 30.00 ± 18.03) and Tabloncillo × Tuxpeño (24 h: 18.33 ± 7.64, 48 h: 25.00 ± 8.66, 72 h: 25.00 ± 8.66) races were the most resistant to red spider mite damage, whereas the most susceptible race was Celaya (24 h: 26.67 ± 15.28, 48 h: 48.33 ± 29.30, 72 h: 65.00 ± 30.00). Further analysis by PCA at 24, 48, and 72 h found the Celaya race positively correlated to growth rate and oviposition of T. merganser and to a lesser extent with the percentage of feeding damage, suggesting that the Celaya race was most susceptible to T. merganser. At 24 h, the Vandeño race was most resistant, given a negative correlation to growth rate and oviposition by T. merganser. The PCA at 48 and 72 h noted the Elotes Occidentales × Tuxpeño race was most resistant to red spider mite, with negative relationships to growth rate and oviposition and, to a lesser extent, to feeding damage. This resistance is due to the differences in both its morphological characteristics and the secondary metabolites present in their leaves.

Evaluation of phenolic antioxidant-linked in vitro bioactivity of Peruvian corn (Zea mays L.) diversity targeting for potential management of hyperglycemia and obesity.

Peruvian corn biodiversity is one of the highest in the world and may represent an important natural source of health relevant phenolic bioactive compounds whose potential needs to be investigated. This study investigated twenty-two Peruvian corn samples corresponding to five corn races (Arequipeño, Cabanita, Kculli, Granada and Coruca) in relation to their total phenolic contents (TPC), anthocyanin contents, Ultra-Performance Liquid Chromatography (UPLC) phenolic profiles and antioxidant capacity (ABTS and ORAC methods). Subsequently using both free and cell-wall bound phenolic fractions their health relevance targeting hyperglycemia (α-glucosidase and α-amylase inhibition) and obesity (lipase inhibition) potentials was evaluated using in vitro assay models. Antioxidant capacity and TPC were high in bound fractions from yellow-colored races in contrast to the purple-colored race (Kculli) which had high TPC (mainly anthocyanins) and antioxidant capacity in the free form. The major phenolic acids detected by UPLC were ferulic and p-coumaric acids. High α-glucosidase (32.5-76.1%, 25mg sample dose) and moderate α-amylase inhibitory activities (13.6-29.0%, 250mg sample dose) were found in all free fractions, but only samples from the Kculli race had lipase inhibitory activity (58.45-92.16%, 12.5mg sample dose). Principal component analysis revealed that the variability of data was affected by the race and the α-glucosidase and lipase inhibitory activities positively correlated with anthocyanins and antioxidant capacity. Some accessions of Kculli, Granada and Cabanita races are promising for future breeding strategies focused on the development of improved corn varieties targeted for the design of functional foods relevant for hyperglycemia and obesity prevention.

Book Reviews

John Hartigan Jr., Care of the Species: Races of Corn and the Science of Plant Biodiversity. Minneapolis, MN: University of Minnesota Press, pp. 376, 2017.Luisa Steur, Indigenist Mobilization: Confronting Electoral Communism and Precarious Livelihoods in Post-Reform Kerala. New York: Berghahn, pp. 302, 2017.

New popcorn races in a diversity microcenter of Zea mays L. in the Far West of Santa Catarina, Southern Brazil

The last classification of corn races in Brazil was performed in 1977, when were described 19 races and 15 sub-races within four groups. However, this classification, which considered the race diversity in Brazil and South American lowlands, did not include popcorns. Therefore, there is a diversity in situ-on farm, which not yet was described after almost 40 years from the last study. This work aimed at identifying popcorn races from populations conserved in situ-on farm in the micro-region of the Far West of the State of Santa Catarina, Southern Brazil, and verifying their relationships with other races of the American continent. Thus, 218 ears of 70 popcorn populations were collected from small-scale farms, aiming to evaluate them for corn descriptors through 16 morphological characters related to ear and kernel. The populations showed variability for all characters, mainly for kernel color. The cluster analysis and principal coordinates, based on Gower index, have highlighted the presence of four distinct groups and one isolated population: I and II Groups, and the population 2279X are not grouped with other popcorn races of Americas, and Groups III and IV have different relationships with other popcorn races of Americas. Thus, in the region of study, there are at least five popcorn races conserved in situ-on farm.

MEXICAN GENOMICS AND THE ROOTS OF RACIAL THINKING

This article confronts the cultural limitation of critical race work in the United States by examining genomic practices at two national institutes in Mexico—one focused on people and aimed at sampling “the Mexican genome,” the other focused on plant biodiversity and “razas de maiz” or races of corn. The human genome project emphasizes admixture in ways that seem to confound claims about the racialization of genomics research in the United States; the biodiversity project highlights the broad extent to which “race” is also about nonhumans. Taken together, these projects suggest a greater breadth and depth to racial thinking than is typically considered in U.S.-based accounts. Grasping this wider scope to race involves, first, foregoing a strict delineation of the social and the biological and, secondly, recognizing that uses of race on nonhumans indicate that racial thinking entails profound questions concerning the nature of species. “Razas de maiz” suggest that racial thinking is both older and more deeply engrained than the modern forms with which we have been most concerned; it may well derive from processes of domestication that are quite ancient and encompass a range of contradictory, complex ideas and practices concerning the relations of humans and nonhumans.

Adaptedness and Heterosis in Corn and Mule Hybrids

The origin of U.S. Corn Belt corn (Zea mays L.), heterotic groups, and heterotic patterns becomes less obvious with more cycles of breeding. Heterosis is poorly understood; simple curiosity cries out for more information. I endeavor to shed light on the effect of adaptedness and heterosis on U.S. Corn Belt corn. I relate pertinent happenings in the phenomenal increase in U.S. corn production. I briefly review the origins of Northern Flint and Southern Dent races of corn and two major, persistent open‐pollinated cultivars; and how corn hybridization was preceded and eased by hybrid species of the horse (Equus spp.). I discuss heterotic groups and patterns. The objective of U.S. corn breeding has been to adapt a tropical crop to a temperate climate. Adaptedness is important. Open‐pollinated cultivars emphasized local adaptation, but some cultivars were more popular, widely grown, and better adapted over a broad geographic region. Hybrid seed corn companies grew larger by selling more widely adapted hybrids that favored germplasm from the more popular, widely grown, better adapted open‐pollinated cultivars containing more genes for adaptedness. I examine morphological differences between inbred parents of a widely adapted hybrid. Relatively constant percentage of heterosis of well‐adapted hybrids over years is due to seasonal climate affecting hybrids and their parent inbreds in a like manner because of their selection for adaptedness. Adaptedness has been more important than heterosis in the U.S. corn yield and production increases. Adaptedness in analogous heterotic species hybrids of the genus Equus, where body size is female dominant, apparently discriminates for body size between mules and hinnies that have virtually identical genotypes—adaptedness determines superiority over and above heterosis.

Genetic variability among Turkish pop, flint and dent corn (Zea mays L. spp. mays) races: Morphological and agronomic traits

32 Turkish corn accessions representing different climatic, geographic and topographic areas in Turkey were identified. Genetic variation and its pattern in three corn races (pop, flint and dent) included 32 accessions were investigated using 25 morphological and agronomic traits. Vegetative, ear and kernel related traits were significantly varied both among races and accessions within races. Variance component due to races and accessions within race were statistically significant, but the variance components due to accessions were generally made up large component of total variance and ranged from 17.17% in kernel length to 82.75% in tassel length. There were also strong and mostly positive correlations between studied agronomic traits as well as between agronomic traits and isoenzyme loci. These correlations were explained by the traditional farming practices and enzyme specificity with flint accessions since the enzyme systems such as Alcohol dehydrogenase (locus 1), Malate dehydrogenase enzyme (loci 2–3) and 6-phospho-gluconate dehydrogenase (locus-1) are generally considered to be the characteristics of flint corn race. Canonical discriminant function analysis with twenty-five morphological and agronomic traits revealed that first two canonical discriminant variables explained 68% of total variation among accessions. Two Canonical variables, in which kernel related traits were heavily weighted, correctly classify the three corn races – indicating that Turkish corn accessions maintained their racial characteristics with agronomic and morphological traits.

Thermal and Functional Characterization of Starch from Argentinean Corn

ABSTRACTScreening accessions in a germplasm bank aids in the identification of plants with unusual properties ranging from agronomic traits to functional and compositional traits of the seed itself. Results from this study confirm the presence of a wide variation in the thermal and functional properties of starch from several landraces of corn in the Argentinean germplasm. Thermal properties of starch measured using differential scanning calorimetry (DSC) identified several corn landraces with properties of potential commercial interest. The pasting and textural properties of gels obtained from starch of different corn landraces also exhibited considerable variability. The degree of variation in thermal and functional properties of corn reported in this study is comparable to the thermal properties of starch from several other crop species. These corn races show promise for further regeneration to create inbred lines with unusual traits. The potential for further improvement of corn races exists not only based on thermal properties, but directly for specific functional attributes as well. Correlation analyses suggest that the variability in thermal and functional attributes are a function of amylose content, granule size distribution and, possibly, differences in the structural makeup of amylose and amylopectin. The strong correlation observed between the thermal properties and pasting and textural properties will allow for the estimation of starch properties from small sample sizes.

Genetic variability among Turkish pop, flint and dent corn (Zea mays L. spp. Mays) races: Enzyme polymorphism

To determine magnitude and pattern of genetic variation, 32 Turkish corn accessions available from the USDA/ARS North Central T-Regional Plant Introduction Station (NCRPIS) collections (Ames, Iowa), representing pop, flint and dent corn races, different climatic, geographic and topographic areas in Turkey, were identified and, 19 isozyme systems were studied. Thirty-nine alleles were detected by 19 isozyme loci in 32 accessions. The PGD-2, Mmm-1, GOT-3 and IDH-1 loci were found to be monomorphic in all accessions. Mean number of alleles per locus varied between 1.2 in Balikesir-167949 accession to 1.7 in Ankara-177600, Trabzon-185062, Eskisehir-204822 and Samsun-239573 accessions. The proportion of polymorphic loci ranged from as low as 15.8% in Balikesir-167949 to as high as 57.9% in Trabzon-185049 accession. Observed heterozygosity was the highest in Adana-183779 and the lowest in Ankara-204800 accession. Genetic identities ranged from 0.823 for 170881-Kocaeli and 167949-Balikesir pair to 0.997 for 182327-Igdir and 168008-Kirklareli pair. Dendrogram constructed by using Nei's genetic distances (1978) revealed three clustering groups, though one of the clusters included only 170881-Kocaeli accession. It is concluded that170881-Kocaeli accession must have experienced with intensive selection, inbreeding and/or bottleneck effects in the past. Corn germplasm managers and breeders could use the results of the present studies for monitoring genetic resources, accession identification, and sampling genetic diversity, but agronomic characteristics of these corn accessions are also needed for a better utlization of Turkish corn land races evolved over the years.

Improved Resistance to Maize Dwarf Mosaic Virus by Selection under Greenhouse Conditions

Maize dwarf mosaic, caused by maize dwarf mosaic virus (MDMV) is the most widespread virus disease of maize (Zea mays L.) in the USA. The objectives of this study were to determine the effectiveness of selecting for resistance to MDMV under greenhouse conditions and to determine if the resistant selections had a gene, presumably Mdm1, for resistance to MDMV that was linked to the endosperm color locus, Y1, on Chromosome 6. One resistant selection was developed from each of six different races of corn crossed with a susceptible hybrid, and two additional resistant selections were obtained out of a synthetic developed in Mississippi. All selections were resistant in field trials in Mississippi. All except one had a higher level of resistance than the field resistant checks in greenhouse tests in Ohio. Three selections had infection levels similar to the highly resistant check inbred, Pa405. Except one, all resistant selections had a gene for resistance linked to the endosperm color locus on Chromosome 6. Apparently, the Mdm1 gene is common in many resistant lines, but the data on one line, Mp92:448, suggest resistance is possible without this gene.

Isozyme Variation and Phylogenetic Relationhips among Open‐Pollinated Sweet Corn Cultivars

Sweet corn (Zea mays L.) is one of the most important vegetables in the USA. But, little is known regarding the phylogeny and diversity among open‐pollinated sweet corn cultivars. To determine the relationship and diversity among sweet corn cultivars, isozyme variability among 60 North American cultivars and four Mexican and two Peruvian sugary1 (sul) populations were compared by principal components analysis (PCA) and cluster analysis (CA). Four major groups were identified: yellow‐kernel sweet corn (‘Golden Bantam’ type), whitekernel sweet corn, Mexican and Amerindian sweet corns, and Peruvian populations. Two cultivars ‘Early June’ and ‘Country Gentleman’ did not fall into any group. The first two groups originated in the northeastern USA. To determine the relationship among sweet corn germplasm and the major North American races of corn, PCA and CA were performed on the isozyme data from the 66 cultivars and populations and mean allele frequencies of the races ‘Northern Flint’ (NF), ‘Southern Dent’ (SD) and ‘Corn Belt Dent’ (CBD). The mean frequencies from NF, SD, and CBD were obtained from previously published data. Northern Flint was grouped with the white and yellow kernel sweet corns, while SD and CBD were grouped with the Mexican and Amerindian cultivars. Fifty‐three of the 60 North American sweet corn cultivars were grouped closely together and could be considered a discrete race, Northeastern Sweets. But, due to the commercial importance of Country Gentleman and the introgression of non‐sweet germplasm into modern sweet corn, we believe that sweet corn should be defined based on its use as a vegetable and on the presence of one or more genes that increase sugar levels in the endosperm.

The Business of Breeding: Hybrid Corn in Illinois, 1890–1940 by Deborah Fitzgerald

TECHNOLOGY AND CULTURE Book Reviews 1117 compare Edison’s innovation strategies, such as his product diversifi­ cation in the 1890s, to later strategies developed at innovative companies in the forefront of industrial research in the 1920s. If the relationship between business strategy and laboratory is a strength of the book, the reader is nonetheless left wishing for a clearer sense of the fiscal state of Edison’s businesses (although the complex nature of the records available for accurately assessing their status will likely require more in-depth study of particular companies than Millard could undertake while researching this book). Readers of Technology and Culture may be disappointed as well by the lack of detailed examination of the actual technical and scientific work of the laboratory at West Orange. This problem is exacerbated by Millard’s failure to provide illustrations of mechanical details. The very inter­ esting photographs that are found in the book too often do not provide information necessary for understanding technical details discussed in the text. Because Millard intends his book to provide “guide posts to the new territory” (p. xiii) he has explored, he can be criticized for not providing a more detailed index and more expansive archival references in the notes. Readers may also wish for a chro­ nology to help them follow the complex trail of changes that took place at the laboratory and in its relationship to Edison’s industrial empire over more than four decades. It is a mark of how much new information is found in this study that the reader wishes for more. Millard has accomplished all that can be asked of a first book on this subject by raising new and important questions for those who follow him into the “vast reaches of the Edison archives” (p. xiii). Paul Israel Dr. Israel is an editor of the Thomas A. Edison Papers at Rutgers University, New Brunswick. The Business of Breeding: Hybrid Corn in Illinois, 1890—1940. By Deborah Fitzgerald. Ithaca, N.Y.: Cornell University Press, 1990. Pp. xi + 247; illustrations, notes, bibliography, index. $29.95. Farming is a complicated business. Its complexity originates in the “nature” of living things and in human attempts to exert biological control. Economic rivalries arise between farmers, as well as among farmers, middlemen, and consumers. And, in various forms, public policy breeds a perplexing mix of interests. Agricultural history, when done well, explains relationships among these three distinct sets of variables—biology, economics, and law—and Deborah Fitzgerald has accomplished this in The Business ofBreeding. On the larger stage, her story of hybrid corn in Illinois is a metaphor for modern agriculture, where science has brought sudden 1118 Book Reviews TECHNOLOGY AND CULTURE change. Fitzgerald says that in 1933, hybrid corn accounted for only .4 percent of total corn acreage in the United States, while a dozen years later it made up 90 percent. In area, that amounted to a rise from some 400,000 acres to nearly seventy-eight million acres, a staggering change by any measure. During the first half of the 20th century, Illinois was the leading corn-producing state, and, not coincidentally, its agricultural college and experiment station made the advance of corn culture its chief mission. Illinois also was home to three private seed companies—Funk Brothers, Pfister, and DeKalb— that helped turn a biological curiosity into a commercial bonanza. Since antiquity, corn growers had known how to cross-pollinate (i.e., take the pollen from the tassels of one plant and sprinkle it on the ear silks of another). Hybridization occurred when crosses between two unrelated races took place—the five races of corn being dent, flint, flour, pop, and sweet. Each race had certain qualities; so, hybrids amalgamated desirable features (and undesirable ones too). In the 1870s, Charles Darwin discovered that it was not the simple act of breeding that produced vigorous progeny but rather the crossing of unrelated varieties. Inbreeding, he observed, increased the frequency of a characteristic’s heredity. Darwin’s book, The Effects ofCross and Self Fertilization in the Vegetable Kingdom (1876), appeared just as the agricultural experiment station movement was taking hold in the United States. This was the spark. An intellectual pedigree exists...

Regional distribution of the growing habit of native corn races (Zea mays L.) over Latin America.

ペルー以南および南米内陸部を除くラテン・アメリカ各地のトウモロコシ27品種32系統(CIMMYTより分譲をうけた)を大阪府(34°35'N、135°35'E)において栽培した。原栽培地とは大きく異なる環境に反応して発現する生育特性によりこれらの在来品種を分類し、生育特性と原栽培地の地理的分布との関係を明らかにすることを目的とした。栽培結果から、特に早晩性、有効雌穂着生数(主稈当たり)、草丈および分けつ数において品種間差があらわれたので、品種比較には主にこれらの測定値を用いた。品種の早晩性は原栽培地の緯度と関連して発現する傾向があったが、一方、緯度に比較的関係のうすい品種間の類似もみられ、それによって供試したすべての品種は次の各地域に分布する5品種群に分類された。I.ウルグアイより西印度諸島に至る大西洋沿岸地帯、II.ユカタン半島を含むメキシコ低地、III.メキシコ中央高原、IV.北部アンデスよりメキシコ南部に至る地域の高地、V.コロンビア・エクアドル太平洋沿岸地帯。各地域内に一分布する品種間にはそれぞれ共通の遺伝子型が拡散し、そのため、同一地域に原栽培地がある品種は互いに類似した生育特性を大阪で発現したと考えられる。すなわち、各地域はトウモロコシの品種分化中心に相当すると考えられた。品種分化中心に関してBRANDOLINI(1970、1971)が行った地理的区分と、上記5地域とは一致しなかった。そこで、ここで得られた結果と従来報告されたラテン・アメリカ在来トウモロコシ品種に関する諸資料(WELLHAUSEN et al. 1952、その他)から品種間類縁関係の広がりについて考察した結果、BRANDOLINIの地理的区分よりはここで得られた5地域への区分の方が品種分化中心として、より合理的であるとの結論を得た。

Variability in callus forming ability of corn races native to Latin America and Nepal.

Variability in callus forming ability of corn races native to Latin America and Nepal.

Agroecologicalcharacteristics of corn races (Zea mays L.) from the different regions of the World. : I. The races native to Prti and Bolivia

Ninety-seven Andean races of maize (Zea mays L.) native to Perti and Bolivia were grown in 1969 in the Experiment Farm of the University of Osaka PreLecture (34°35'N., 135°30'E.). The plants were exclusively delaying to mature in Osaka, especially in the races from 10wer latitudes and altitudes of the native countries. It was often difH:cult to do selfing in some races, especially frorn higher altitudes, because the silking delayed so long time that the ffowering of the tassel did not overlap with the former. Prolonged maturation had made the plants taller with greater number of nodes of the stalk. The longest leaf and the uppermost ear attached at quite high nodal positions, influenced by the altitude of the native cultivation site. Thus, the races were classifed into two grbups: (1) Races from lower altitudes (>1, 000m); The uppermost ear attached at an axil several leaves above the longest leaf. (2) Races from higher altitudes (>1, OOOm); The ear attached at the direct or near node of the longest leaf.

PARAMUTAGENIC SYSTEMS IN SOME SOUTH AMERICAN RACES OF CORN

RINK (1956) reported the occurrence of an unusual phenomenon at the R locus in maize. The “standard” Rr (colored aleurone, colored plant) allele was observed to have decreased pigment producing capacity after being heterozygous (R‘ RSt ) with a “pattern” allele, stippled (R“) . Additional observations by BRINK and WEYERS (1957) showed that marbled (Rmb), another “pattern” allele, also produced the change if brought into the heterozygous condition with R‘. Both RSf and Rnlb produce green plants, but Rmb has a coarser pattern in the aleurone than R”t. The term paramutation was proposed to describe such changes observed at the R locus and the characteristics of the phenomenon have been reviewed elsewhere (BRINK 1958a). The change was found to be genetic, transmitted through the eggs and the sperm, to occur regularly in Rr gametes derived from R‘ RSt or R‘ Rmb heterozygotes and to revert partially toward the standard R‘ level when made homozygous. BRINK, BROWN, KERMICLE and WEYERS (1960) observed that Rg (colored aleurone, green plant) also could be paramutated. BROWN and BRINK (1960) observed that both paramutated alleles Rr.st and Rg:st acquired some paramutagenic properties from the inducing source. Other paramutagenic sources have been observed. ASHMAN (1960) isolated non-purple (T‘) mutants from Rr R”t heterozygotes and found some of these to be paramutagenic and others not. MCWHIRTER and BRINK (1962) tested 83 self-color (Rsc) mutants of RSt alleles and found that they varied from “strongly paramutagenic” and “weakly paramutagenic” to “non-paramutagenic” apparently in a continuous series. The basis of the phenomenon was found to be chromosomal at the R region and not the result of plastid or other cytoplasmic factor inheritance (BRINK 1958b). A series of 24 South American races of corn with variegated aleurones (marbled-like and stippled-like phenotypes) have been tested and their effects on the standard R‘ are described. The study reported here revealed that paramutagenicity is common in sources with variegated aleurones. A brief report of some of these results appeared earlier (LINDEN 1963).

Plant Material from a Cave on the Rio Zape, Durango, Mexico

AbstractPlant remains from La Cueva de los Muertos Chiquitos consist mostly of cultivated plants, beans, corn, and cucurbits. The inhabitants also gathered acorns, pinon nuts, black walnuts, and opuntia fruits for food, and used yucca, agave, and possibly cotton for fibers. The beans are unusually abundant and diverse: three species and 12 types or varieties. A type of lima bean (Phaseolus lunatus) and two common beans (P. vulgaris), one of them similar to the cultivar Wells Red Kidney, are new to the Southwest and to northwestern Mexico. The lima bean is of interest because it belongs to the round-seeded Carib group with a center of diversification in the West Indies, whereas other lima beans from the prehistoric Southwest are mostly small-seeded and flat, probably derived from Central America. Five races of corn are represented: an ancient race called Chapalote; Cristalina de Chihuahua, the most numerous race in the collections; Onaveño, a race with medium-sized, hard-flint kernels; Pima-Papago, the common soft flour corn of the Arizona-Sonora border; and Toluca Pop, a central Mexican pyramidal, pointed popcorn. Cob fragments and grains show definite evidence of hybridization with Tripsacum or teosinte. Three species of cultivated Cucurbitaceae, a wild species of Cucurbita, and a species of Apodanthera were identified. Fragments of gourds, mostly Lagenaria siceraria, are relatively abundant. Seeds and peduncles of Cucurbita pepo occur in strata throughout the entire profile. Cucurbita mixta was found in the later strata, but remains of this species are meagre. Seeds of Apodanthera sp. may have been used for food. A single wood sample from near the base of the midden produced a radiocarbon date of A.D. 660 (1300 ± 100 B.P.).

Analysis of Maize from the Four Bear Site and Two Other Arikara Locations in South Dakota

Previous articleNext article No AccessAnalysis of Maize from the Four Bear Site and Two Other Arikara Locations in South DakotaHugh Cutler and George A. AgoginoHugh Cutler Search for more articles by this author and George A. Agogino Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 16, Number 3Autumn, 1960 Article DOIhttps://doi.org/10.1086/soutjanth.16.3.3629034 Views: 3Total views on this site Citations: 2Citations are reported from Crossref Journal History This article was published in the Southwestern Journal of Anthropology (1945-1972), which is continued by the Journal of Anthropological Research (1973-present). PDF download Crossref reports the following articles citing this article:Major M. Goodman, William L. Brown Races of Corn, (Oct 2015): 33–79.https://doi.org/10.2134/agronmonogr18.3ed.c2James B. Griffin, Volney H. Jones The University of Michigan Excavations at the Pulcher Site in 1970, American Antiquity 42, no.33 (Jan 2017): 462–490.https://doi.org/10.1017/S0002731600092684

Morphogenetic Differences Between Nicotiana alata and N. Langsdorffii as Indicated by Their Response to Indoleacetic Acid

An unusual opportunity for the application of the present knowledge of hormones to the investigation of morphogenetic differences between two closely related species is afforded by Nicotiana alata and Nicotiana Langsdorffii. The flowers of the two species are similar, but the difference in the size of the corolla parts suggests a possible interpretation in terms of hereditary response to growth substance. One of the chief differences lies in the constricted part of the corolla-tube (pl. 25, fig. 1). In N. alata its length is at least fifteen to twenty times that of N. Langsdorffii, whereas the whole corolla in the former is only four or five times the length of the latter. The epidermal cells of the tube of N. alata are extremely long; those of N. Langsdorffii, relatively short. The work on several known genetic dwarf races of corn by van Overbeek ('35, '38) indicates that the varietal differences are 'due to genetic differences which regulate production, use, and inactivation of auxin. The experiments on Epilobium hybrids by Schlenker and Mittman, cited by Went and Thimann ('37), suggest this same relationship. If this hypothesis holds true for species of Nicotiana and the differences between them are due to differences in amount of hormone produced, then auxin should prove to be a limiting factor in N. Langsdorffii and its application to the corollas of this species should then cause an increase in size. If differences are due to differences in ability to use growth substance, then auxin should be a limiting factor in N. alata and additional amounts should increase