Genetic Variation For Yield Research Articles

Estimation of genetic variation in yield, its contributing characters and capsaicin content of Capsicum chinense Jacq. (ghost pepper) germplasm from Northeast India.

Capsicum chinense Jacq. (ghost pepper), a naturally occurring chili species of Northeast India is known throughout the world for its high pungency and a pleasant aroma. The economic importance is due to the high capsaicinoid levels, the main source for pharmaceutical industries. The present study focused on identifying important traits necessary for increasing the yield and pungency of ghost pepper and to determine the parameters for the selection of superior genotypes. A total of 120 genotypes with more than 1.2% capsaicin content (>1,92,000 Scoville Heat Unit, w/w on dry weight basis) collected from different northeast Indian regions were subjected to variability, divergence and correlation studies. Levene's homogeneity test of variance studied for three environments did not show significant deviation and so homogeneity of variance was reasonably met for analysis of variance study. Genotypic and phenotypic coefficient of variation was highest for fruit yield per plant (33.702, 36.200, respectively), followed by number of fruits per plant (29.583, 33.014, respectively) and capsaicin content (25.283, 26.362, respectively). The trait number of fruits per plant had maximum direct contribution to fruit yield per plant and the trait fruit yield per plant towards capsaicin content in the correlation study. High heritability with high genetic advance, which is the most favored selection criteria was observed for fruit yield per plant, number of fruits per plant, capsaicin content, fruit length and fruit girth. The genetic divergence study partitioned the genotypes into 20 clusters, where fruit yield per plant contributed maximum towards total divergence. Principal components analysis (PCA) studied to determine the largest contributor of variation showed 73.48% of the total variability, of which the PC1 and PC2 contributed 34.59% and 16.81% respectively.

Appraisal of genetic variability in sodium azide induced rice mutants to identify selection criteria for higher yield using quantitative attributes

Induced mutation is an effective tool in generating variability of crop plants. Identification of efficient genotypes with improved yield requires knowledge of genetic variation in yield and yield contributing traits. Therefore, an investigation was conducted to develop variants through azide mutagenesis and estimation of genetic variability of the mutants to detect selection standards towards higher yield. Mature rice seeds were mutagenized with estimated LD50 concentration. A hundred mutants were grown-up accordingly and their quantitative traits were evaluated through multivariate analysis to assess genetic variability. Every assessed trait except grain length exhibited highly significant variation for all mutants. The high genotypic and phenotypic coefficient of variation along with high heritability and genetic advance as a % of mean was accounted for total and filled grains panicle-1. Grain yield was positively and significantly correlated with total grains panicle-1, filled grains panicle-1 and straw yield hill-1. Besides, higher variance was also associated with these traits. Ward’s Agglomerative clustering grouped the mutants into 7 major clusters. More than 36% of total variation was associated with first 2 principal components (PCs) and was mostly with total grains panicle-1 and filled grains panicle-1 whereas third and fourth PCs were mainly accounted for straw yield hill-1. Thus, these traits should receive special attention during selection of yield potential genotypes. Presence of genetic variation in mutants was ensured for most of the traits and selection based on greater tillers hill-1, grains panicle-1 and straw yield hill-1 may open a new avenue towards improved yield and other traits in rice.

Morphological variations of wheat (Triticum aestivum L. em. Thell.) under variable ethyl methanesulphonate mutagenesis

Genetic gains in wheat yield have stagnated over the years due to genetic drift. There is a need to create new genetic variation for yield using various methods including ethyl methanesulphonate (EMS). The use of EMS mutagenesis is limited by variations in lethality, efficiency and effectiveness, which confound to selection. The objective of this study was to evaluate morphological variation in wheat after EMS mutagenesis. Wheat genotype LM43 was subjected to EMS mutagenesis under the following conditions: 0.1% v/v for 1 h at 25 °C, 0.1% v/v for 1 h at 30 °C and 0.7% v/v for 1.5 h at 25 °C. Some mutant plants in M1 had significantly (p < 0.05) higher spikelets per spike and kernels per spike. The number of tillers and kernels per spike increased significantly at M2 generation. EMS treatment with 0.1% v/v for 1 h at 30 °C was the most effective and efficient with the lowest biological damage. Macro-mutations were observed in spike, peduncle, awn and flag leaf morphology. The study identified early generation mutants that could be exploited for improving drought tolerance, yield and biomass, or for genetic analysis to identify quantitative trait loci in wheat.

Genetic and Physiological Aspects of Drought Tolerance in Smooth Bromegrass

ABSTRACTThe genetic basis of physiological traits and their association with forage yield and drought tolerance is poorly understood in smooth bromegrass (Bromus inermis Leyss). In this study, half‐sib families from a polycross population were evaluated in the field under normal and water deficit conditions during 2012 and 2013. Water deficit greatly influenced physiological traits and forage production. Under water deficit conditions, most of physiological traits decreased, whereas carotenoid content, proline content, and ratio of chlorophyll a/ chlorophyll b increased. Moderate to high estimates of heritability and genetic variation for yield and physiological traits indicated that selection in this germplasm would be useful in achieving genetic progress. Heritability estimates were slightly decreased for agromorphological traits under water deficit conditions, but the heritability of physiological traits increased in response to water deficit conditions. Significant associations between drought tolerance index and chlorophyll a, chlorophyll b, total chlorophyll content, carotenoids, and proline content showed the importance of these traits to confer drought tolerance in smooth bromegrass. Several genotypes with relatively higher tolerance and forage yield were identified under both moisture regimes that can be used in further breeding programs of smooth bromegrass.

Physiological and Metabolic Responses of Rice to Reduced Soil Moisture: Relationship of Water Stress Tolerance and Grain Production.

Access to adequate irrigation resources is critical for sustained agricultural production, and rice, a staple cereal grain for half of the world population, is one of the biggest users of irrigation. To reduce water use, several water saving irrigation systems have been developed for rice production, but a reliable system to evaluate cultivars for water stress tolerance is still lacking. Here, seven rice cultivars that have diverse yield potential under water stress were evaluated in a field study using four continuous irrigation regimes varying from saturation to wilting point. To understand the relationship between water stress and yield potential, the physiological and leaf metabolic responses were investigated at the critical transition between vegetative and reproductive growth stages. Twenty-nine metabolite markers including carbohydrates, amino acids and organic acids were found to significantly differ among the seven cultivars in response to increasing water stress levels with amino acids increasing but organic acids and carbohydrates showing mixed responses. Overall, our data suggest that, in response to increasing water stress, rice cultivars that do not show a significant yield loss accumulate carbohydrates (fructose, glucose, and myo-inositol), and this is associated with a moderate reduction in stomatal conductance (gs), particularly under milder stress conditions. In contrast, cultivars that had significant yield loss due to water stress had the greatest reduction in gs, relatively lower accumulation of carbohydrates, and relatively high increases in relative chlorophyll content (SPAD) and leaf temperature (Tm). These data demonstrate the existence of genetic variation in yield under different water stress levels which results from a suite of physiological and biochemical responses to water stress. Our study, therefore, suggests that in rice there are different physiological and metabolic strategies that result in tolerance to water stress that should be considered in developing new cultivars for deficit irrigation production systems that use less water.

Responses to phosphorus among barley genotypes

Genetic improvement in phosphorus (P) use efficiency (i.e. the ratio of biomass or yield at nil P to that at a given rate of application) is an important goal to improve P recovery and P efficiency of farming systems. Experiments were conducted at three sites in South Australia between 2009 and 2011 to characterise genetic variation in yield with no applied P and in the response to P fertiliser among a diverse range of barley (Hordeum vulgare L.) genotypes. In each experiment, 39–54 genotypes were grown at 0 or 30 kg P/ha. Responses to P were measured near the beginning of stem elongation by using normalised difference vegetation index (NDVI) and by harvesting the grain. Rhizosheath size was also measured on seedlings. Consistent differences in growth and yield at 0 kg P/ha were measured among the genotypes. By contrast, there were large environmental effects on responses to P, but some genotypes showed consistent responses. Measurements of growth, yield and P uptake on a subset of genotypes showed that most of the variation in biomass and yield could be attributed to variation in P-uptake efficiency (net total P uptake per unit available P) rather than to P-utilisation efficiency (biomass or yield per unit total P uptake). The size of the rhizosheath made a small contribution to variation in NDVI but not grain yield, suggesting that rhizosheath size may be of some benefit to early growth but that this does not persist through to yield. Genetic correlations between NDVI and yield were often weak but were generally positive at 0 kg P/ha. Correlations between responses in NDVI and responses in grain yield were low and often negative. The study identified several barley genotypes that showed consistent differences in yield at low P and responses to P; however, selection for P efficiency based solely on responses in vegetative growth may not be appropriate. Variation in P uptake appeared to be more important than P-utilisation efficiency for P efficiency in barley.

Genetic Variation for Yield and Yield Components in Sole Soybean and Soybean/Celosia Inter-Crop in Makurdi (Southern Guinea Savanna Ecology), Nigeria

Genetic Variation for Yield and Yield Components in Sole Soybean and Soybean/Celosia Inter-Crop in Makurdi (Southern Guinea Savanna Ecology), Nigeria

Genetic variation for vigour and yield of cocoa (Theobroma cacao L.) clones in Ghana

The lack of agronomic information on germplasm clones has been suggested as one of the reasons for their poor utilization and management. Several cocoa genotypes from different genetic origin have been introduced into Ghana to broaden the crops genetic base. The present study investigates genetic variation and associations of vigour (estimated as stem diameter increments) and yield and its component traits (bean weight, number of beans per pod, pod value and yield efficiency) in 116 cocoa clones introduced into Ghana over different time periods. The clones were transplanted in June 2010, after eight-months of grafting, following a randomised complete block design with four replications consisting of four trees per clone per block. Stem diameter increments (SDI) in both juvenile and productive stage and yield component traits were evaluated between July 2010 and June 2015. Clone effects were highly significant (P<0.01) for all the traits except SDI in the productive stage. Pod value and bean yield varied from 14 to 57 and 183 to 952kg/ha, respectively. Heritability was generally low for all the traits and the highest observed (0.27±0.06) was for bean weight. A positive genetic correlation (r=0.47, P≤0.001) was observed between SDI in the juvenile stage and bean yield. Some of the best performing clones T65/238, ICS 40, T16/613, SGU 50 and T63/961 combined high yields with high bean weight and high yield efficiency. Results from the study indicate that there is considerable genetic variation for yield in the available germplasm clones, and yield increase could be achieved by developing hybrids from some of the best clones.

Genetic variation and selection within glandless cotton germplasm

There is a renewed interest in research and use of glandless (free of gossypol) Upland cotton (Gossypium hirsutum L.) that can produce edible seeds for human food and animal feed. However, there was a lack of information on yield potential of existing glandless germplasm since intermittent breeding activities for glandless cotton were stopped in the U.S. before 2000. The objectives of the present study were to test obsolete and exotic glandless germplasm for possible production and evaluate progress in direct pedigree selection within the existing glandless germplasm in eight field tests. In multiple tests, the glandless cotton Acala GLS yielded only 65–80 % lint of the glanded control Acala 1517-08 and 46–75 % lint of commercial transgenic cultivars. Most of obsolete glandless germplasm and their selections yielded <70 % of Acala 1517-08 and only three selections yielded 82–89 % of the control. Genetic variation in yield and fiber quality traits was seen from significant differences between selections within the same glandless germplasm, indicating the existence of residual genetic variation. Most importantly, three selections from exotic glandless germplasm out-yielded Acala 1517-08 by 4–9 %, one of which had desirable fiber quality traits. These promising glandless lines with comparable yields to commercial cotton make it possible to revitalize the glandless cotton industry. More field tests will be needed to evaluate their yield potential and adaptability in the U.S. Cotton Belt.

Genetic variation in yield under hot ambient temperatures spotlights a role for cytokinin in protection of developing floral primordia

Unusually hot ambient temperatures (HAT) can cause pre-anthesis abortion of flowers in many diverse species, limiting crop production. This limitation is becoming more substantial with climate change. Flower primordia of passion fruit (Passiflora edulis Sims) vines exposed to HAT summers, normally abort. Flower abortion can also be triggered by gibberellin application. We screened for, and identified a genotype capable of reaching anthesis during summer as well as controlled HAT conditions, and also more resistant to gibberellin. Leaves of this genotype contained higher levels of endogenous cytokinin. We investigated a possible connection between higher cytokinin levels and response to gibberellin. Indeed, the effects of gibberellin application were partially suppressed in plants pretreated with cytokinin. Can higher cytokinin levels protect flowers from aborting under HAT conditions? In passion fruit, flowers at a specific stage showed more resistance in response to HAT after cytokinin application. We further tested this hypothesis in Arabidopsis. Transgenic lines with high or low cytokinin levels and cytokinin applications to wild-type plants supported a protective role for cytokinin on developing flowers exposed to HAT. Such findings may have important implications in future breeding programmes as well as field application of growth regulators.

Assessing the importance of subsoil constraints to yield of wheat and its implications for yield improvement

Many of the soils in the Australian cereal belt have subsoils with chemical and physical properties that restrict root growth, which limits water use and yield. On alkaline sodic soils salinity, high pH, high available boron (B), deficiencies of zinc (Zn) and manganese (Mn) and high soil strength occur commonly and aluminium (Al) toxicity restricts root growth on acid soils. While the effects of individual subsoil constraints have been studied there is some debate about the relative importance to yield of the different soil stresses across the region. To address this issue yield variation among a set of 52 varieties of bread wheat was analysed using yield data from 233 trials conducted over 12 years. The trials were conducted in all mainland States but the majority were in South Australia and Western Australia. Each variety was characterised for its response to high B, high pH, Al toxicity, salinity, deficiencies in Zn and Mn and resistance to root lesion nematode (Pratylenchus neglectus), root growth through strong soil, seminal root angle, carbon isotope discrimination (CID) and maturity. This data was then used to examine the contribution of each trait to the genetic variation in yield at each of the 233 trials. The contribution of a specific trait to the genetic variation in yield at each site was used to infer the importance of a particular constraint to yield at that site. Of the traits linked to soil constraints, salinity tolerance, (measured by Na+ exclusion) was most often associated with genetic variation in grain yield (34% of all experiments), followed by tolerance to high Al (26%) and B tolerance (21%). Tolerance to low Zn and Mn were not consistently associated with yield variation. However, maturity was the trait that was most frequently associated with yield variation (51% of experiments), although the relative importance of early and late flowering varied among the States. Yield variation was largely associated with early flowering in Western Australia and the relative importance of late flowering increased as trials moved eastward into South Australia, Victoria and New South Wales. Narrow, rather than wide, seminal root angle was more commonly associated with high yield (25% of sites) and there was little evidence of any regional pattern in the importance of root angle. CID was important in 18% of trials with a low CID being most commonly associated with high yields. The yield advantage at sites where a trait contributed significantly to yield variation ranged from ~15% for Na+ exclusion and B tolerance to 4% for tolerance to high pH. The analysis has provided an assessment of the relative importance of a range of traits associated with adaptation to environments where subsoil constraints are likely to affect yield and has indicated patterns in the importance and effects of these traits that may be linked to regional variation in rainfall and soils.

Genetic variation in yield and fatty acids of Jatropha curcas L.

Thirty three Jatropha curcas plants of four year age growing under uniform conditions were evaluated with respect to seed yield, oil content and fatty acid profile. The seed yield varied from 485 to 2115 g per plant. Significant genetic variation was observed for oil content which ranged from 19.72 to 38.04 percent. The promising genotypes showing superiority for oil yield were G33, G15, G35, G19 and G29. Four fatty acids also witnessed significant differences among the genotypes. J. curcas oil contained 78.91 percent total unsaturated fatty acids (oleic acid and linoleic acid) and 19.83% saturated fatty acids (palmitic acid and stearic acid). The significant genotypic variation offered huge scope of improvement.

Genetic variation in yield of five hybrids of sweet corn grown under poultry manure and nitrogen fertilizers and the presence of the nitrate reductase gene (Nia2)

Concern about nitrate (NO3−) accumulation in plants and its hazard to human and animal health has led to the investigation of the genetic variation in its accumulation in plants.Genetic variation in the productivity and nitrate content of sweet corn hybrids (Zea mays L.) when produced under five treatment combinations of chemical nitrogen fertilizer and poultry manure was investigated. In addition, the presence of the nitrate reductase gene (Nia2) in hybrids of sweet corn was investigated by PCR analysis. The chlorophyll content of leaves was higher with chemical fertilizer and the mixture of chemical fertilizer and chicken manure compared with chicken manure only. The highest grain yield was recorded in the hybrid Amera grown with chicken manure or the mixture of nitrate fertilizer and poultry manure. Moreover, gene-specific primer pairs for amplification of nitrate reductase revealed the presence of the nitrate reductase gene (Nia2) in hybrid Merit, which had the lowest grain nitrate content. Moreover, Merit only had one extra band (900 bp) indicating the Nia2 gene was controlled by co-dominant alleles. However, the presence of nitrate reductase gene (Nia2) alone did not explain nitrate content differences among corn hybrids. The work presented in this paper showed that PCR assays represent a sensitive tool for screening of sweet corn breeding material for the Nia2 gene although the presence of this gene does not alone explain nitrate content. Key words: Genetic variation, Low nitrate concentrations, sweet corn, nitrate reductase gene (Nia2), PCR

Genetic Variation for Yield and Fiber Quality Response to Supplemental Irrigation within the Pee Dee Upland Cotton Germplasm Collection

ABSTRACTWater availability is a major factor influencing cotton cultivar performance and sustainable cotton (Gossypium hirsutum L.) production in the southeastern USA. An increased understanding of the response of diverse cotton germplasm lines to supplemental irrigation could aid in future efforts to develop cultivars targeted to irrigated or dryland environments. In this study, 13 germplasm lines were selected from the Pee Dee (PD) germplasm collection and evaluated to measure the effect of supplemental irrigation on a number of agronomic and fiber quality traits important to cotton production systems. Most PD germplasm lines receiving supplemental irrigation had increased plant height and lint percent, while boll weight, seed index, fiber length, fiber strength, uniformity index, and micronaire decreased. Cultivars PD‐2 and FM‐966 did not show a significant response to supplemental irrigation for any of the traits measured. In contrast, PD5377 and PD93009 showed differential responses to supplemental irrigation for 5 out of the 12 traits measured. This study shows the importance of comparing individual genotype response to supplemental irrigation for agronomic and fiber quality traits to efficiently target genotypes for irrigated or dryland environments.

Temperate Maize Inbreds Derived from Tropical Germplasm: I. Testcross Yield Trials

Tropical maize (Zea mays L.) has been suggested as a germplasm source to improve yield and disease resistance for U.S. breeding programs. Our objective was to compare the performance of testcrosses between tropical‐derived lines and an elite U.S. tester with the performance of adapted commercial hybrids. A group of 190 lines was derived from seven tropical commercial hybrids and intercrosses among them using two cycles of pedigree selection for adaptation to North Carolina. Ear‐to‐row sib‐mating and selfing were used to develop the lines. Visual selection of each generation concentrated on silk‐tassel synchrony, earliness, standability, lower ear height, and ear quality. No selection for combining ability was made during line development. Lines were topcrossed onto the public U.S. single cross B73Ht/Mo17Ht. Testcrosses were evaluated in yield trials at three locations during 2 yr. Among 190 testcrosses, 16 were within the LSD (0.05) of the commercial checks for yield, standability, and grain moisture. Most genetic variation for yield, standability, and grain moisture was accounted for by differences among pedigrees rather than differences among lines within a pedigree. Seventeen testcrosses yielded more than the tester, B73Ht/ Mol7Ht. The inbreds B73 and Mo17 represent two dominant heterotic groups utilized by U.S. maize breeders. Since tropical‐derived lines appear to combine well with B73/Mo17, they could be used as a source of disease resistance for either heterotic group. In addition, they have potential to enhance the combining ability of inbreds representing these two heterotic groups.

The Effectiveness of Early Generation Testing as Applied to a Recurrent Selection Program in Peanut1

Abstract The effectiveness of early generation testing for yield improvement in peanut (Arachis hypogaea L.) was evaluated in an attempt to increase the efficiency of an on-going recurrent selection program by reducing the time required for evaluation and selection. The objectives of the study were to (1) determine if the number of years required per cycle of selection could be reduced; and (2) estimate the amount of genetic variability remaining in the population for yield and four agronomic traits after four cycles of recurrent selection. Sixty-eight random-mated crosses, among the 40 highest yielding lines from the cycle 3 population, were evaluated for yield and agronomic traits in 1985 (S0:1), 1986 (S0:2), and 1987 (S0:3). The results were compared to determine if early generation performance accurately predicts the performance of cross bulks in later generations. No significant correlations were found for yield of entries in the S0:3 and S0:2 or in the S0:3 and S0:1; however, there was a significant correlation between yield of entries in the S0:2 and S0:1 generations. No correlations were found between yield and any of the agronomic traits measured in the S0:3; however, significant correlations were found in the S0:2 between yield and most traits measured. Significant correlations were also found for entries in the S0:3 and S0:2 generations for each agronomic trait measured except number of seed per 20 pods. Early generation testings appears to be useful for selection of certain agronomic traits, but of limited value when selecting for yield. A decrease in genetic variation for yield in the population from the S0:1 to the S0:3 generation was observed; however, the number of crosses equal to or exceeding the yield of the check cultivar increased in later generations. All agronomic traits measured, except number of seed per 20 pods, showed significant genetic variation remaining in the population in both the S0:2 and S0:3 generations. The greater the genetic variation remaining in the population for a given trait, the more likely it is that further improvement of that trait will be realized with additional cycles of selection.

A note on the effect of variation of lactation length on the efficiency of tropical cattle selection for milk yield

The effects of procedures generally used to reduce variation of lactation length on the efficiency of selection for milk yield are examined applying existing theory to a set of average literature estimates of heritabilities and correlations between lactation yield and length. Adjustment of milk yield for lactation length should be expected to remove more genetic than phenotypic variation, thus reducing selection efficiency in relation to unadjusted yield. Selecting individuals on an optimum index of lactation yield and length would be more efficient for improving yield than selecting on yield alone, while both criteria would have practically the same efficiency for selection on progeny test. This result could be applied to reduce milk recording frequency without losing selection accuracy. Culling on lactation length before selecting on yield would have little effect on individual selection efficiency. However, excluding short lactation records should be expected to reduce both selection accuracy of the progeny test and genetic variation in yield.

Gene differences in heading date, height, seed weight and seed yield between two pure line varieties of Triticum aestivum L.

Reciprocal sets of homozygous inbred backcross lines were developed by crossing two pure line varieties (Baart 46 and Ramona) of Triticum aestivum L., followed by two backcrosses to each of the two parent varieties, and six to eight generations of selfing. Data on each inbred backcross line was obtained from twelve plots (from replications in three years). Five genes were responsible for over 95% of the genetic variation for heading date. These genes had pleiotropic effects on plant height that were proportional to their effects on heading date. Two additional genes had detectable effects on plant height. The genes with a measurable effect on height accounted for 90% of the genetic variation in the Baart 46 genetic background. One gene affected seed weight. In the Ramona background, this gene accounted for 80% of the genetic variation in seed weight and 16% of the genetic variation in seed yield. Two genes, responsible for the earliest and latest heading date classes, had large pleiotropic effects on seed yield. They accounted for 60% of the genetic variation in yield. One gene, with no effect on heading date, caused a detectable reduction in yield of 23% in the Baart 46 inbred backcross lines. This gene had no apparent effect in the Ramona genetic background. Quantitative trait genes are sparsely distributed in the genome: fewer than one in four chromosome arms carries a gene with a detectable effect. Gene effects on quantitative traits are not small and similar. The distribution of 22 gene effects for heading date and height is slightly skewed to the right: as the magnitude of effect increases, the frequency of genes having the effect decreases.

The variation for some characters in cowpeas, Vigna unguiculata (L.) walp following ionizing radiation

Ojomo O. A. and Chheda H. R. The variation for some characters in cowpeas , Vigna unguiculata ( L. ) Walp following ionizing radiation . Radiation Botany 12 , 373–380, 1972.—The genetic variation for yield, pods per plant, and time to flowering in two varieties of cowpeas, ‘Westbred’ and ‘Local Brown’ was studied in the M 3 generation following radiation with X-rays and neutrons. The materials were planted in double row plots with two replications. Analysis of data showed that the genetic variance in the irradiated populations were higher than in the control, in the range of 1·2–8 times. ‘Local Brown’ had higher variability than ‘Westbred’ following ionizing radiation, this has been attributed to the more primitive evolutionary status of ‘Local Brown’. The means of irradiated and control populations of the two varieties were not significantly different except for yield of ‘Westbred’ and time to flower of ‘Local Brown’ where means of irradiated populations were lower and higher than the respective control populations. By using pods per plant as a selection index, it was possible to make selections from irradiated populations of ‘Westbred’, which on the average yielded higher than similar selections from the control population.

Genetic Variation in Yield and Quality of Oat Forage1

We evaluated 30 cultivars of oats (Avena sativa L.) for forage quality and yield at heading and 10 days later in 1968. Quality traits measured included in vitro digestible dry matter (IVDDM), cell wall constituents (CWC), acid detergent fiber (ADF), acid detergent lignin (ADL), and crude protein (CP) concentration. Eleven of the cultivars were tested for 2 additional years.All three fiber components (CWC, ADF, and ADL) were positively correlated with each other and all were negatively correlated with IVDDM. Of the three, however, ADL was most closely associated with digestibility. Yield and quality were negatively correlated at heading, but independent 2 weeks later. Forage yield and grain yield were not associated. Forage yield was correlated with plant height and heading date.Cultivars differed in oat forage quality within a given environment; differences, however, generally were not repeatable over years. In contrast, cultivar variation for forage yield was consistent over years and sufficient for effective selection. Therefore, we recommend primary emphasis on forage yield in the developmnt of superior forage oat cultivars. However, one should examine forage quality before making final selections.