Showing papers in "Crop Science in 1964"
TL;DR: It is found that improvements in efficiency are unlikely so long as only "final" characters such as yield and quality are considered and that real progress will be possible only as the authors clarify the pathways by which final characters are reached.
Abstract: THERE is rather general agreement amongst plant breeders that interactions between genotype and environment have an important bearing on the breeding of better varieties. However, it is much more difficult to find agreement as to what we ought to know about genotype-environment interactions and what we should do about them. Some breeders emphasize the camouflaging effect of such interactions on the \"value\" of genotypes. Consequent ly they attempt to estimate the magnitude of variances attributable to interactions and to ultilize such estimates in developing ever more precise methods of selection. Other breeders feel that improvements in efficiency are unlikely so long as only \"final\" characters such as yield and quality are considered. They believe that real progress will be possible only as we clarify the pathways by which final characters are reached. Still others maintain that what is needed is a direct and pragmatic approach which will tell us what types of genetic systems are most likely to give high and stable performance. The literature on genotype-environmental interactions is very large. It varies from reports of variety trials in the field to consideration of the mechanisms which allow cells containing the same genes to become as different as a pollen
775 citations
TL;DR: The objectives of the present investigation were to estimate for 2 soybean, Glyc'me max (L.) Merr.
Abstract: ESTIMATES of heritability, the advance expected by selection and the interrelationships among such traits as seed yield, plant height, lodging, maturity, protein percent, and oil percent are useful in designing an effective breeding program. Such estimates are of most value when based upon material grown under different environments as to years and locations. The objectives of the present investigation were to estimate for 2 soybean, Glyc'me max (L.) Merr., crosses: (1) heritability, (2) progress to be expected from selection, (3) variance due to genotype, genotype-environment interactions and error, and (4) interrelationships among 9 traits.
289 citations
TL;DR: It is found that at osmotic pressures greater than atmospheres, alfalfa seed germination in solution cultures was retarded considerably more by concentrations of NaC1 than by mannitol presumably because of the toxic effect of the salt.
Abstract: ACCUMULATION of salts in the irrigated soils of western United States often results in reduction of seed germination and planet growth, Plant genera and species may differ widely in salt tolerance but, for most crops, varietal differences in salt tolerance are very small. Approximately a third of the soils of the Imperial Valley of southern California are excessively saline and are usually cropped to the more salt tolerant crop species. Ogasa (12) found ~:hat seed germination of soybean variety ~KO 561’ was inhibited by a 0.2% NaC1 solution at 30° C. but it was necessary to increase the concentration to 0,3% NaC1 to cause inhibition at 15° C. The data of Uhvits (15) show that at osmotic pressures greater than atmospheres, alfalfa seed germination in solution cultures was retarded considerably more by concentrations of NaC1 than by mannitol presumably because of the toxic effect of the salt. Rudolfs (13) found seed water absorption in 15 hours was decreased 9% when the osmotic pressure of the germinating solution was increased from 0 to 7 atmospheres with addition of NaC1. Ayers and Hayward (2) showed that salt tolerance during seed germination is not always positively correlated with that of the crop during later growth. The first physiological reaction of plants immediately after an increase in soil salinity is reduced entry of water in roots (3, 9). Reduced growth, which is not yet clearly understood, follows. Reduced growth is evident in reduced height and development of smaller, darker green leaves (6, 8, lo). The characteristic chloride toxicity symptoms for peach, citrus, and a number of other trees are incipient chlorosis accompanied by drying and browning of the leaf beginning at the margin of the apex. The minimal levels of chloride accumulation associated with leaf burn o.f several fruit trees ranged from 5,000 ppm ~co 18,000 ppm chloride (4). Leaves of field, vegetable, and forage crops which usually showed no specific chloride injury in salinized soil ranged from 17,750 ppm to 53,000 ppm chlorides. Bernstein and Ayers (5) found no relation between chloride content and salt tolerance in green beans. In their studies, 6 varieties of green beans all accumulated large amounts of chloride. Although barley (1) and co~ton (11) were considered highly salt tolerant, varietal differences in salinity effects on seed yield were reported. Salt decreased the vegetative portions of barley and wheat relatively more than that of the grain (1). The ’Lee’ soybean variety was rated moderately salt tolerant in studies at the U.S. Salinity Laboratory at Riverside, California, a in 1955. In this study, seed yields were reduced 50% when the electrical conductivity of the saturation extract of the soil, (ECe) was 9 millimhos/cm. Oil percentage decreased and protein percentage increased slightly. Preliminary studies with 50 soybean strains adapted to
249 citations
108 citations
TL;DR: Studies of the effects of variations of temperature and water deficit on leaf photosynthetic rates were initiated using the leaf chamber technique, and high temperatures and water deficits were found which depressed leaf photosynthesis rates.
Abstract: Studies of the effects of variations of temperature and
& water deficit on leaf photosynthetic rates were initiated
using the leaf chamber technique. The two factors were
varied independently; high temperatures and water deficits
were found which depressed leaf photosynthetic rates.
Stomatal widths were also measured.
98 citations
TL;DR: The optimum environment is one which will elicit the greatest differential genetic manifestation for the attribute in question (assuming, of course, that different genetic potentials exist within the population under test).
Abstract: W HAT constitutes an optimum environment in which to practice selection for an attribute? Obviously, the optimum environment is one which will elicit the greatest differential genetic manifestation for the attribute in question (assuming, of course, that different genetic potentials exist within the population under test). In some cases defining the optimum environment is easy. For example, oat plants which possess the A gene for reaction to stem rust (giving a resistant reaction to races 7 and 7A) can be differentiated from those carrying the a gene by subjecting the plants to infection with spores of stem rust race 7. Other factors of the environment (temperature, soil moisture, etc.) can vary over rather wide ranges without seriously affecting the reaction conditioned by the A and a ~enes.
87 citations
TL;DR: This report is concerned with interspecific matings of haploids in maize, which is affected by the choice of both the pistillate and the "pollen" parents and the possibility of similar results with the potato.
Abstract: 1 Crops Research Division, ARS, USDA and Departments of Horticulture and Genetics, University of Wisconsin. Cooperation of the Inter-Regional Potato Introduction Project (IR-1) in providing Solanum materials is acknowledged. This investigation is supported in part by a grant from the National Science Foundation. Received for publication May 27, 1964. 3 Geneticist, Crops Research Division, ARS, USDA, and Professor; Geneticist, CRD, ARS, USDA, and Associate Professor; and Graduate Assistant, respectively. ing interspecific matings, some means of markedly increasing their frequency must be found if stockpiles of haploids are to be readily accumulated. The frequency of haploids in maize is affected by the choice of both the pistillate and the \"pollen\" parents (2). Previous work with the potato indicated the possibility of similar results (5). This report is thus concerned with:
77 citations
75 citations
TL;DR: Work at this station and independent work in Australia and Pakistan uncovered safflower types with a very low level of linoleic acid and a high level of oleic acid.
Abstract: 'T'HE increasing interest in the oil of safflower (Cartha-*• mus tinctorius L.) for edible purposes has been based on its high level of polyunsaturation or, in other words, on its high content of linoleic acid. This interest has prompted safflower researchers to take a closer look at the fatty acid composition of their materials. Work at this station (2, 3) and independent work in Australia (1) and Pakistan (4) uncovered safflower types with a very low level of linoleic acid and a high level of oleic acid. The difference in oil quality from the normal type was due mostly to a single gene. The fatty acid constitution of these types is similar to that of olive oil. In 1959, E. M. Nelson, Agricultural Advisor with U. S. Operations Missions in Iran, obtained a sample of safflower seed from a shop in the town of Mianeh, in the Azerbaijan. It was given the plant introduction number 254,717 by the U. S. Department of Agriculture and was grown at the Regional Plant Introduction Station at Pullman, Washington, in 1959. Oil from bulk open-pollinated seed of
67 citations
TL;DR: Electrophoretic migration of several other substances including silver, copper, 2,4oD, and a stem rust toxin have been studiedn and the path of migration was observed to be restricted to the liquid between protoplasts.
Abstract: U normal conditions for growth, water is distributed between the space inside and outside of the living protoplasts in a balanced relationship (3, 5, 6, 8). The outer liquid, as contrasted to the inner liquid, forms a continuous system throughout the tissues where solutes can diffuse freely. The outer liquid is located along the cell walls, in spaces between cells, and in xylem vessels. Freezing causes redistribution of water with respect to both location and state (7). The pattern of redistribution of water during freezing determines the type and extent of stress (10). Some patterns of redistribution and, therefore, some types of freezing stress affecting various regions of plants can be distinguished by the electrophoretic method. This method is based on the principles of electrophoresis, on investigations of the path of migration of electrolytes through plant tissues in an electric field, and on studies of electrical properties of films over surfaces uch as cellulose. Briefly, application of the method consists of measuring the direct current which passes between two electrical contacts on the plant at a series of low voltages. Data are taken continuously as the temperature is gradually lowered. Studies of electrical properties and limitations of plant tissues and the migration path of indicators such as charged dye molecules howed that the weak direct electric current was conducted by migration of electrolytes through the continuous liquid system between living protoplasts (9, 10). The amount of liquid between protoplasts depends on the type of tissue and the moisture content of the plant. Usually most of the water is inside the protoplasts (in the protoplasm and vacuoles). Estimates of water in the free space have been as high as 23% for normal barley roots and 24.5 to 33.5% for normal wheat roots (2, 4). Corrections by Levitt indicate that the free space may be as low as 10% (8). In any case there is sufficient liquid to support electrophoresis of introduced substances along the cell walls in normal tissue (9, 10). Since mobility of these substances is greatly affected by plant moisture content it seems that liquid in the free space must also vary. Amaranth, a negatively charged dye, was used in many experiments to find the path of current through leaves, roots, and crowns of cereals and leaves of Canada thistle ~ (9, 10). The path of migration was observed to be restricted to the liquid between protoplasts. Other substances uch as methyl-ene blue which are taken up by the protoplasts also were seen moving along the cell walls in the same manner as they do in a strip of moist filter paper through which a weak direct current is flowing. Electrophoretic migration of several other substances including silver, copper, 2,4oD, and a stem rust toxin have been studiedn (9, 10). Anderson et al. used this technique to study the mobility of calcium (1). While foreign substances introduced into
TL;DR: The problem of alkaloid conversion is most intriguing in that it affects not only the concentrations of total alkaloids, but also of nicotine and its various decomposition products of which nornicotine is at present considered the most intriguing.
Abstract: THE primary and predominant alkaloid in the cured leaves of most of the varieties of Nicotiana tabacum L. is nicotine. Certain "low-nicotine" varieties, however, possess the inherent capability of demethylating appreciable amounts of nicotine thereby converting it to nornicotine (5, 6, 16). In fact, in most if not all commercial tobacco types individual plants with high nornicotine content can be found (1, 2, 6, 10, 12, 13, 16, 19). The problem of alkaloid conversion is most intriguing in that it affects not only the concentrations of total alkaloid, but also of nicotine and its various decomposition products of which nornicotine is at present considered the
TL;DR: The effects of ice, snow, and water covers on the winter survival of bluegrass and bentgrass are elucidated to elucidate the relationships between ice sheets and winter injury.
Abstract: W INTER injury of sports turf has recently become of increasing concern in the north central and northeastern United States. The basic components of these turf areas are common Kentucky bluegrass (Poa pratensis L.), annual bluegrass (Poa annua L.), and creeping bentgrass (Agrostrs palustris Huds.). They are usually maintained under conditions of close mowing, irrigation, and high fertility. In general, injury has been associated with an ice cover with annual bluegrass being the most susceptible species. The relationships between ice sheets and winter injury of bluegrass and bentgrass are not well defined. This study was undertaken to elucidate the effects of ice, snow, and water covers on the winter survival of bluegrass and bentgrass.
TL;DR: It likely will be several years before sufficient data are available to determine the types of gene action responsible for heterosis in self-pollinated crops, and programs for improving source populations should be designed so that selection utilizes most efficiently the typesof gene action which contribute toheterosis in the species.
Abstract: THE utilization of male sterility to produce commercial hybrids in self-pollinated and often-cross-pollinated crops creates new problems and at the same time new opportunities in methods of breeding these crops. Methodology worked out for cross-pollinated crops must be modified in most cases to be used efficiently for self-pollinated crops. One of the problems common to all hybrid breeding programs is acquiring source populations. Past years of breeding have made available an abundance of superior pure lines for producing hybrids in crops such as sorghum (S. vulgare Pers.) and in wheat [T. aestivum (Vill., Host) MacKey], which is on the threshold of hybrid production. Perhaps because of this wealth of pure lines, breeders will not immediately recognize the need to develop new source populations from which superior lines could be selected. However, developing good source populations is usually a long-time project, and the grace period granted by previous years of effective breeding could be used to initiate programs of population improvement for future years. Programs for improving source populations should be designed so that selection utilizes most efficiently the types of gene action which contribute to heterosis in the species. However, it likely will be several years before sufficient data are available to determine the types of gene action responsible for heterosis in self-pollinated crops. Reciprocal recurrent selection, as described by Comstock et al. (1), theoretically changes the gene frequencies in two populations so that overdominant, dominant, and partially dominant loci are all eventually utilized for maximum genetic advance. Comstock et al. did not elaborate on the effectiveness of this type of selection with respect to epistatic loci. They did suggest that an increase in the frequency of favorable combinations of epistatic loci seemed likely. Until it is
TL;DR: A knowledge of the genetics of resistance to leaf rust resistance, caused by the rust organism Puccinia recondita Rob.
Abstract: A KNOWLEDGE of the genetics of resistance to leaf •*\"*• rust of wheat, Triticum aestivum L., caused by the rust organism Puccinia recondita Rob. ex. Desm., would greatly reduce the empiricism involved in practical rust breeding programs and hasten product ion of resistant varieties. Breeding for leaf rust resistance is complicated by the occurrence of many physiologic races of the causal organism. A total of 183 physiologic races has been registered by Johnston (8).
TL;DR: The major reason for the poorer survival of the white genotypes became apparent during the development of an isogenic line in which heterozygosity was maintained at the basic color locus: white seeds within this line had considerably lower emergence under field conditions than colored seeds.
Abstract: THE presence or absence of pigment in the seed coat of lima beans (Phaeseolus lunattis L.) is determined by a single locus (1). When only the recessive allele c is present at this basic color locus, no pigment is produced and the seed coat is white. In the presence of the dominant allele C, pigment is formed but the particular color of the pigment depends on genes at several other loci. Whether or not the seed coat is pigmented might be expected to have little relationship to adaptation. However, white seeded lima beans have been found to be strikingly inferior to colored seeded individuals under population conditions (2). The major reason for the poorer survival of the white genotypes became apparent during the development of an isogenic line in which heterozygosity was maintained at the basic color locus: white seeds within this line had considerably lower emergence under field conditions than colored seeds. This paper is concerned with the underlying causes of this difference and some of their genetic, evolutionary, and agronomic implications.
TL;DR: Understanding the growth responses of perennial grasses is important to an understanding of their growth responses and was a Rockefeller Foundation Post-Doctorate Fellow during the 1962-63 school year at the University of Wisconsin.
Abstract: 1 Contribution from the Department of Agronomy, Wisconsin Agricultural Experiment Station, Madison. Published with approval of the Director, Wisconsin Agr. Exp. Sta. Received Dec. 17, 1963. 3 Post-Doctorate Fellow and Professor of Agronomy, respectively, Wisconsin Agr. Exp. Station. The senior author was a Rockefeller Foundation Post-Doctorate Fellow during the 1962-63 school year at the University of Wisconsin, while on leave from the Institute of Agricultural Research, Tohoku University, Sendai, Japan. This financial assistance from The Rockefeller Foundation is gratefully acknowledged. of perennial grasses is important to an understanding of their growth responses.
TL;DR: Naturally occurring plant estrogens have been reported to increase growth rate of sheep and Cheng and Burroughs (6) stated that "while exces-
Abstract: IT HAS long been known that estrogenic substances occur in forage plants and that their occurrence may affect animal performance As early as 1946 sheep infertility was associated with estrogenic subterranean clover (Tri folium subterraneum L.) in Australia (2), and the problem appeared to be greater when the soil was deficient in phosphorus (1). Naturally occurring plant estrogens have been reported to increase growth rate of sheep (13, 15). Cheng and Burroughs (6) stated that \"while exces-
TL;DR: There was a range in fertility primarily between crosses, a fact which must be considered when a more critical genetic analysis is made of this nondehiscent character.
Abstract: The sorghum variety 9E, a selection made in Ghana, Africa, used as the female, was crossed to the sorgo variety 'Leoti' at the Department of Agriculture Exper imen t Station, Samaru—Zaria, Nigeria, in 1951. The objective was to improve the forage quality of African sorghum varieties. A few seeds of this cross were planted in the greenhouse at the Nebraska Agricultural Experiment Station, Lincoln, Nebraska, in the fall of 1951. The anthers of the Fi appeared to be fully developed but failed to dehisce. The sterile Fj plants were pollinated with pollen from Leoti. Subsequent crosses were made using pollen from the varieties 'Combine Kafir-60', 'Redbine-60', and 'Martin'. The Fi plants from these crosses also were sterile and by 1962 six backcrosses to the three recurrent parents had been made. While these backcrosses were being made, other varieties including the original 9E parent were crossed to the steriles and their Fi progenies were studied. Over 100 varieties were crossed to derived nondehiscent sterile Martin at Lincoln, Nebraska, in 1962 for the purpose of determining if any variety would produce a fertile hybrid. The Fi plants were checked for fertility in the greenhouse and in the field in 1963 by bagging 10 heads prior to anthesis. The seed set on the Fj heads was estimated visually into class intervals of 5%. The class intervals of 20 to 30% used to classify the seed set on the heads from the F» plants was probably more realistic and sufficiently accurate for this study. The main consideration of this paper is to emphasize that there was a range in fertility primarily between crosses, a fact which must be considered when a more critical genetic analysis is made of this nondehiscent character. Anthers in various stages of development from Martin malesterile and male-fertile plants were collected at the Experimental Farm at Bichpuri, Agra ( India) , during the seasons of 1962 and 1963, and were fixed in formalin-acetic alcohol for microtomy. The fixed anthers were dehydrated and infiltrated through an ethyl