Direct and indirect selection for grain yield in oats (avena sativa L.)     

S. K. Johnson  D. B. Helsel  K. J. Frey 《Euphytica》1983,32(2):407-413

Direct and indirect selection for increased grain yield were carried out on a population of 678 F₂-derived lines of oats. A selection intensity of 10% was used with direct selection (selection for grain yield itself) and with indirect selection using three criteria, harvest index, vegetative growth rate, and the index of harvest index + vegetative growth rate. Expected gains from 1978 evaluations were compared to actual gains measured in 1980. Actual grain yield increases were 4, 8, 7, and 6% from selection via harvest index, vegetative growth rate, grain yield, and harvest index + vegetative growth rate, respectively. Thus, indirect selection via vegetative growth rate gave a greater increase in grain yield than did direct selection. Heritability values computed via components of variance ranged from 0.50 to0.57 for the three traits, harvest index, vegetative growth rate, and grain yield, whereas regression heritabilities ranged from 0.41 to 0.55. Realized heritabilities were 0.33, 1.00 and 0.89 for the three traits, respectively. Selection via all criteria caused significant changes in nearly all agronomic traits except weight per volume. Vegetative growth rate, which gave the greatest gain in grain yield, caused less drastic changes in days to anthesis, plant height, biological yield, and vegetative yield than did direct selection for grain yield.  相似文献   

Diallel analysis among 16 maize populations adapted to the northern U.S. Corn Belt for grain yield and grain quality traits     

Tonette P. Laude  Marcelo J. Carena 《Euphytica》2014,200(1):29-44

Genetically diverse germplasm is needed to increase frequency of favorable alleles of economically important traits in maize improvement. The objectives of this study were to determine the genetic components involved in grain yield and grain quality traits, and provide preliminary assessment of useful heterotic groups and patterns from a large sample of maize populations adapted to the northern U.S. Corn Belt. Sixteen populations were used in the diallel mating design following Gardner–Eberhart Analysis II to estimate variety (v _i ) and heterosis (h _ij ) genetic effects for grain yield and grain quality traits. Specific heterosis (s _ij ) and predicted means of population crosses for grain yield were used to evaluate the heterotic relationships among the populations. Data for grain yield and grain quality traits were generated in partially balanced single lattice experiments across North Dakota (ND) locations in 2010, 2011, and 2012. Analyses of variance showed significant differences among genotypes. Heterosis effects explained most of the differences among diallel entries for grain yield, while v _i effects had greater influence on grain quality traits. NDL, EARLYGEM 21c, NDSCD(FS-CS)C2, NDSS, and NDSM(M-FS)C9 were identified as elite populations for grain quality improvement. NDSS × NDBS22(R-T1)C9 and NDBS1011 × EARLYGEM 21c showed high s _ij effects for grain yield with good grain quality. NDSS and EARLYGEM 21c represent stiff stalk synthetic (SSS) group, and NDBS1011 fall under non-SSS group. Further studies need to validate the heterotic group of NDBS22(R-T1)C9. Recurrent and pedigree selection programs will be established for selected populations and population crosses to integrate pre-breeding with cultivar development.  相似文献   

Variation in Rauvolfia serpentina genetic resources in India     

N. R. Bhagat  S. P. Mital  M. W. Hardas 《Euphytica》1980,29(3):747-750

Summary Rauvolfia serpentina (L.) Benth. ex Kurtz genetic resources from several regions of India were evaluated at New Delhi in the period 1970–76 to understand the variation pattern for root yield and associated polygenic traits. The Uttar Pradesh populations represented the wides range of diversity for most of the traits; the populations from Assam possessed high root yield potential. In other states, too, variation was evident. On the basis of variation pattern, areas in the Indian subcontinent were identified for collection and conservation of Rauvolfia germplasm.  相似文献   

Genetic variability and interrelationship of traits in the industrial oil crop Vernonia galamensis     

Tesfaye Baye  Heiko C. Becker 《Euphytica》2005,142(1-2):119-129

Vernonia galamensis is a wild plant from the family Asteraceae which is endemic to East Africa and has the potential to become a new oil crop for industrial uses. Its seed oil is rich in vernolic acid, a fatty acid of high interest for oleochemical applications. However, a breeding program for Vernonia galamensis cultivars with high seed and oil yields requires knowledge about the genetic variability of traits that influence seed and oil production. This study was undertaken to examine phenotypic and genotypic variability, broad-sense heritability, genetic advance under selection and interrelationships of agronomic and seed quality traits. A total of 122 Vernonia accessions, 115 collected from different regions of Ethiopia and seven introduced, were grown at two locations in Ethiopia (Alemaya and Babile), in 2001/2002 and were analyzed for 20 traits including phenology, yield, yield components, and seed quality with special emphasis on fatty acid composition. The collections exhibited significant variation for all traits except for days to emergence. Genotypes and locations interacted significantly (P 0.01) for all traits. Broad-sense heritability estimates ranged from 11% (for days to emergence) up to 79% (for days to maturity). Expected genetic advance was between 1.3% (for days to emergence) and 44.8% (for seed oil yield). Genetic correlation analysis revealed that seed yield per plant is highly and positively correlated with seed weight and head number; highly significant and negative correlations (r = –0.59, –0.82, –0.85, and –0.89) were found between vernolic acid and palmitic, stearic, oleic, and linoleic acid, respectively. Highly significant positive correlations (r = 0.55, 0.44, and 0.36) were observed between vernolic acid and oil content, meal protein content and seed oil yield, respectively. Path-coefficient analysis indicated seed weight and secondary head number to be the most important components of seed yield per plant. Vernolic acid, oleic acid and linoleic acid had positive direct effects and stearic acid had a negative direct effect on oil content. The direct positive effect of oleic acid on oil content was, however, compensated by the negative indirect effects of stearic and vernolic acid resulting in a negative correlation (r = –0.60) between oleic acid and oil content. These observations will support the selection of accessions with high seed and oil yield, high meal protein contents, and high vernolic acid content.  相似文献   

Exploring ethyl methanesulfonate (EMS) treated cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) to improve drought tolerance     

Travis W. Witt  Mauricio Ulloa  Mathew G. Pelletier  Venugopal Mendu  Glen L. Ritchie 《Euphytica》2018,214(7):123

The Texas High Plains often has extended periods between rainfall events, which can lead to a reduction in the yield and fiber quality of cotton (Gossypium hirsutum L.). It is known that cultivated cotton suffers from low levels of genetic diversity due to the over-use in breeding of similar gene pools, which may hinder breeding for drought tolerance. In this study, for the first time the novel variability or genetic diversity of morphological and agronomic traits possibly created by the chemical mutagen ethyl methanesulfonate (EMS) was evaluated to improve drought tolerance in cotton by traits’ response to different irrigation regimes. EMS is a chemical mutagen that has been shown to cause point mutations in the DNA of many model plants and crop species. Three EMS treated lines were advanced from the M₁ to M₄ generation as bulk-harvested populations. A diverse selection scheme was applied to capture most of the genetic trait-variability or diversity and superior lines in these populations. In 2014–2016 the diversity of these populations was evaluated based on four agronomic and thirteen morphological traits to determine differences in response to multiple irrigation rates. Analyses of these traits showed statistically significant (p?≤?0.05) differences between and within populations when compared to the original non-treated EMS source, with most of the variability being observed in the high irrigation rate. However, none of the EMS treated populations had significantly (p?≤?0.05) better lint yield than the commercial cultivar (control) in 2016. EMS yield performance was possibly constrained by the applied diverse selection scheme of this study. Traits such as total number of bolls, bolls retained at node 7 and below, and those retained between nodes 8 and 12, and bolls retained at node of first fruiting branch may be predictors to improve cotton production (yield) in water limiting environments.  相似文献   

Why SR52 is such a great maize hybrid? II. Heritability,correlation and path-coefficient analyses     

Tatenda R. Musimwa  John Derera 《Euphytica》2017,213(3):62

Although exceptional heterosis for yield in the world’s first commercial single cross maize (Zea mays L.) hybrid SR52 has been confirmed, the role of secondary traits hasn’t been established. Objectives of this study were to establish relationship between grain yield and secondary traits, while assessing heritability and genotypic variation in SR52’s segregating populations. Knowledge on associations between yield and secondary traits would be crucial in extracting productive inbred lines from the population. Traits were subjected to correlation and path-coefficient analyses. Path analysis model accounted for over 70% of variation (R²) in all populations. Consistently high positive correlations with grain yield were observed for ear length and number of kernel rows on ear. Ear girth (0.19), and number of kernels per row (0.48) showed high direct effects on yield in the F₂ population and the trend was consistent in the backcrosses. Positive indirect effects of most traits on grain yield were negligible with the exception of kernel per row via total number of kernels on ear, which was above 0.40 in the F₂ and BCP1. Ear length can be exploited for indirect selection for yield in SR52’s segregating generations. 100-kernel weight and number of kernel rows on ear can, to a lesser extent, be targeted in selecting for grain yield. High to medium phenotypic variability in segregating generations of SR52 for traits such as ear length, number kernel rows on ear and grain yield should give impetus to selection of productive inbred lines from SR52 hybrid because of presence of diversity in the gene pool.  相似文献   

Phenotypic variation in root architecture traits and their relationship with eco-geographical and agronomic features in a core collection of tetraploid wheat landraces (<Emphasis Type="Italic">Triticum turgidum</Emphasis> L.)     

Magdalena Ruiz  Patricia Giraldo  Juan M. González 《Euphytica》2018,214(3):54

To obtain varieties with root systems adapted to marginal environments it is necessary to search for new genotypes in genetically diverse materials, such as landraces that are more likely to carry novel alleles for different root features. A core collection of ‘durum’ wheat, including three subspecies (dicoccon, turgidum and durum) from contrasting eco-geographical zones, was evaluated for root traits and shoot weight at the seminal root stage. Distinctive rooting phenotypes were characterized within each subspecies, mainly in subsp. durum. Contrasting rooting types, including large roots with shallow distributions, and others with high root numbers were identified. Correlations with climatic traits showed that root shape is more relevant in adaptation to eco-geographical zones in subsp. dicoccon, whereas in subsp. turgidum and durum, which come from warmer and drier areas, both size and shape of roots could have adaptive roles. Root traits with the largest positive effects on certain yield components under limited water conditions included root diameter in subsp. dicoccon, root size in turgidum, and root number in durum. Additionally, shoot weight at the seedling stage had important effects in subsp. turgidum and durum. Twenty-eight marker–trait associations (MTAs) previously identified in this collection for agronomic or quality traits were associated with seminal root traits. Some markers were associated with only one root trait, but others were associated with up to six traits. These MTAs and the genetic variability characterized for root traits in this collection can be exploited in further work to improve drought tolerance and resource capture in wheat.  相似文献   

Genetic variability and interrelationships of seed yield and yield components in switchgrass     

Modan K. Das  Charles M. Taliaferro 《Euphytica》2009,167(1):95-105

Information on the genetic variability of seed yield and yield components is limited and no information is available on correlations among seed yield and yield components and direct and indirect effects of the yield components on seed yield in switchgrass, Panicum virgatum L. Accordingly, we conducted replicated experiments at Chickasha and Perkins, OK, in 1998 involving 11 lowland type switchgrass populations to assess genetic variation for seed yield and yield components, quantify interrelationships among them, and determine direct and indirect effects of yield components on seed yield through path coefficient analysis to identify traits for indirect selection of seed yield. Significant (P ≤ 0.01) variation existed among the 11 populations over locations for percent seed set and 100-seed weight. Seed yield/plant and the seed yield components panicle number/plant, spikelet number/panicle, and seed number/panicle had significant (P ≤ 0.05) population × location interactions, indicating substantial environmental influence on these traits for these populations. Accordingly, data for these traits were analyzed separately for each location revealing significant (P ≤ 0.01) differences among populations at both locations for each of these traits. Phenotypic correlation between seed yield/plant and seed number/panicle was positive (r = 0.76** at Chickasha and r = 0.72** at Perkins). Path coefficient analyses revealed that seed number/panicle had the highest positive direct effect on seed yield at both locations. Ample genetic variability was present among the switchgrass populations studied to allow breeding improvement of seed yield. Selection for increased seed number/panicle would be the most effective means of indirectly selecting for higher seed yield within this germplasm. Correlation and path coefficient analyses among biomass yield, seed yield, and harvest index indicated that, at least within the switchgrass germplasm studied, it would be possible to breed switchgrass cultivars with enhanced biomass yielding ability and sufficient seed production capability for their commercial propagation.  相似文献   

Root architectural traits and yield: exploring the relationship in barley breeding trials     

Hannah Robinson  Alison Kelly  Glen Fox  Jerome Franckowiak  Andrew Borrell  Lee Hickey 《Euphytica》2018,214(9):151

Root system architecture is fundamental to resource capture and productivity of cereal crops. Understanding the genetics modulating root development will empower plant breeders to design cultivars with optimal root systems for the target environment. Here, we investigate the genetic association between seminal root traits and yield in elite barley (Hordeum vulgare L.) germplasm. A panel of 216 breeding lines from the Northern Region Barley Breeding program in Australia, genotyped with Diversity Arrays Technology markers, were characterised for seminal root angle and number. A high degree of phenotypic variation was evident in the population, ranging from 12.0° to 89.4° and 4.8 to 6.1 for root angle and number, respectively. A quantitative trait locus for root angle (qRA-5) was detected on chromosome 5H and co-located with the previously described RAQ2. The genetic relationship between seminal root traits and yield for the panel was investigated using root phenotypes and yield data from 20 field trials. Genetic correlations with yield ranged from ??0.21 to 0.36 for root angle and from ??0.20 to 0.25 for root number. The direction and magnitude of the correlations for both root traits varied across the environments, but overall root angle was deemed more strongly associated with yield. Here we provide insight into the root phenotypes of breeding lines and deliver a first look at the genetic relationship between root architectural traits and yield in barley breeding trials.  相似文献   

Effect of the inbreeding depression in progeny fitness of runner bean (Phaseolus coccineus L.) and it is implications for breeding     

Ana M. González  Antonio M. De Ron  María Lores  Marta Santalla 《Euphytica》2014,200(3):413-428

Moderate levels of selfing despite high inbreeding depression (ID) make runner bean an excellent model for mixed-mating reproductive biology studies in legumes. This work assesses the extent of the ID variation and consistency at different plant growth stages through selfing generations in seven runner bean populations. Field-collected populations after previous isolated multiplication were hand-pollinated in an isolated greenhouse during five generations to produce progeny. Generations were compared for inbreeding effects (δ) on seed germination, survival to flower, and seed weight and yield. The outcrossing rates of the founder populations and the genetic variation and Wright’s ID at the population and generation level were estimated by using 35 polymorphic microsatellite loci. Neutral microsatellite loci were analyzed through generations and populations using different outlier tests to identify loci directly associated with adaptation to inbreeding. Our study revealed patterns of genetic diversity (H _e  = 0.36) and outcrossing rates (ranged from 24 to 44 %) that are consistent with a mixed-mating system. Selfing-pollination procedure significantly affected germination and survival rates, yield, and to a lesser extent seed weight. Three loci had significant hits to genes related to embryonic development when performing BLAST searches to Phytozome database. Results showed a general inconsistency in δ across plant growth stages and populations, suggesting that different deleterious loci are acting at different stages. Inbreeding tended to purge individuals of deleterious recessive alleles to reduce ID. Variation among individuals within populations may lead to the development of inbreeding lineages with lower levels of ID. Several lines that have been self-pollinated for many generations became homozygous at almost all gene loci and produced a uniform population of true breeding progeny and acceptable performance.  相似文献   

Variation and covariation for Gibberella ear rot resistance and agronomic traits in testcrosses of doubled haploid maize lines     

Matthias Martin  Wolfgang Schipprack  Thomas Miedaner  Baldev S. Dhillon  Bettina Kessel  Milena Ouzunova  Albrecht E. Melchinger 《Euphytica》2012,185(3):441-451

Gibberella ear rot (GER) of maize caused by Fusarium graminearum reduces grain yield and leads to contamination of the grains with deoxynivalenol (DON), a mycotoxin that adversely affects the health of humans and animals. The objectives of this study were to (1) analyze means and genotypic variances for line per se performance (LP) and testcross performance (TP) of doubled haploid (DH) lines for GER severity and DON concentration as well as for some agronomic traits, (2) examine correlations among these traits, (3) validate QTL for resistance detected in previous studies for LP and their effect on TP and (4) investigate the relative efficiency of indirect selection (RE) for LP to improve TP. Testcross progenies of 94 DH lines originating from four flint populations were developed using a susceptible dent tester as pollinator. Artificial inoculations with F. graminearum led to appreciable disease development. Average TP for GER severity and DON concentration were lower than the mean mid-parent values of the tester and DH lines, indicating mid-parent heterosis for resistance. Genotypic variation for resistance was significant for LP and TP. Genotypic correlations between LP and TP were low and resistance QTL for LP had no significant effects on TP. Accordingly, RE for resistance was low, suggesting to allocate resources mostly to the evaluation of testcrosses. Correlations of resistance to GER and DON contamination with grain yield (measured under non-inoculated conditions) were not significant, indicating that selection for resistance and higher grain yield can be carried out simultaneously.  相似文献   

Evaluation of morpho-physiological traits of MRQ74 pyramided lines with drought yield QTLs     

Asmuni Mohd Ikmal  Zainuddin Nurasyikin  Arvind Kumar  Abd Aziz Shamsudin Noraziyah 《Euphytica》2018,214(6):98

Drought regularly affects rainfed lowland and upland rice ecosystems in Malaysia. Three drought yield QTLs, viz qDTY _2.2 , qDTY _3.1 and qDTY _12.1 successfully pyramided into MRQ74 to increase its yield under reproductive stage drought stress (RS). Forty-eight genotypes comprising 39 pyramided lines (PLs) with different qDTYs combinations, four parents including MRQ74 (recipient) and five checks were evaluated for morpho-physiological traits under RS and non-stress (NS). This study aims to determine which traits influenced by individual qDTY and qDTY combinations and to gain better understanding of QTL interactions in enhancing grain yield (GY) under RS. Results showed plant height, number of panicles, root length, root weight, relative water content and 100-grain weight increased while chlorophyll content and GY decreased under RS compared to NS. No significant difference was observed in days to flowering, leaf rolling and grain length between selected PLs and MRQ74 under RS. Six PLs with yield advantage (YA) of 208.17–1751.63 kg ha^?1 compared to MRQ74 in RS but yielded similar to MRQ74 under NS were further selected. Under RS, qDTY class analysis showed qDTY _12.1 individually and combination qDTY _12.1  + ?qDTY _2.2 produced the highest yield of 1521.77 and 1092.30 kg ha^?1 respectively. qDTY _12.1 as single or combination with other qDTY is the best qDTY in stabilizing GY under RS. PL-77 with qDTY _12.1 is the best PL with YA of more than 1100 kg ha^?1 compared to MRQ74 in both RS and NS conditions can be recommended for cultivation in normal and drought-prone areas.  相似文献   

Variance components and heritability of traits related to root: shoot biomass allocation and drought tolerance in wheat     

I. Mathew  H. Shimelis  L. Mwadzingeni  R. Zengeni  M. Mutema  V. Chaplot 《Euphytica》2018,214(12):225

Enhanced root growth in plants is fundamental to improve soil water exploration and drought tolerance. Understanding of the variance components and heritability of root biomass allocation is key to design suitable breeding strategies and to enhance the response to selection. This study aimed to determine variance components and heritability of biomass allocation and related traits in 99 genotypes of wheat (Triticum aestivum L.) and one triticale (X. Triticosecale Wittmack) under drought-stressed and non-stressed conditions in the field and greenhouse using a 10?×?10 alpha lattice design. Days to heading (DTH), days to maturity (DTM), number of tillers (NPT), plant height (PH), spike length (SL), shoot and root biomass (SB, RB), root to shoot ratio (RS), thousand kernel weight (TKW) and yield (GY) were recorded. Analyses of variance, variance components, heritability and genetic correlations were computed. Significant (p?<?0.05) genetic and environmental variation were observed for all the traits except for spike length. Drought stress decreased heritability of RS from 47 to 28% and GY from 55 to 17%. The correlations between RS with PH, NPT, SL, SB and GY were weaker under drought-stress (r?≤???0.50; p?<?0.05) compared to non-stressed conditions, suggesting that lower root biomass allocation under drought stress compromises wheat productivity. The negative association between GY and RS (r?=???0.41 and ??0.33; p?<?0.05), low heritability (<?42%) and high environmental variance (>?70%) for RS observed in this population constitute several bottlenecks for improving yield and root mass simultaneously. However, indirect selection for DTH, PH, RB, and TKW, could help optimize RS and simultaneously improve drought tolerance and yield under drought-stressed conditions.  相似文献   

Evaluating interspecific wheat hybrids based on heat and drought stress tolerance     

Mohamed?I.?HassanEmail author  Elsayed?A.?Mohamed  Mahmoud?A.?El-rawy  Karam?A.?Amein 《Journal of Crop Science and Biotechnology》2016,19(1):85-98

Three durum and three bread wheat genotypes were crossed to produce three tetraploid, three hexaploid and nine interspecific (pentaploid) F₁ hybrids. All genotypes were evaluated for heat tolerance in the field and for drought using polyethylene glycol in vitro. Chromosome numbers and meiotic behavior in pentaploid F₁ hybrids (2n=5x=35, genomes AABBD) were confirmed. Heat stress significantly reduced grain yield/plant and 1000-kernel weight (1000-KW), while grain protein content (GPC) was increased. Drought caused a significant reduction in root length, shoot length and seedling fresh weight, whereas root/shoot ratio was increased. P₃ (durum), P₄ (bread) and their pentaploid F₁ hybrid could be considered as the most heat-tolerant genotypes. However, P₂ (durum), P₆ (bread) and their F1 were most tolerant to drought. The addition of a D genome single dose into pentaploid F1 hybrids obviously reduced grain yield/plant, 1000-KW and seedling traits, however GPC was increased. Moderate to high broad-sense heritability and genetic advance were obtained for the most investigated traits. Grain yield/plant was strongly positively correlated with stress tolerance index (STI), yield index (YI), mean productivity (MP), geometric mean productivity (GMP) and harmonic mean (HM) under heat stress and with root length under drought condition, suggesting that STI, YI, MP, GMP and HM are powerful indices for heat tolerance, while root length is most effective for drought. Successful interspecific hybridization obtained in the study is only an initial step for desired genes introgression. Successive progenies are going to be evaluated for further genetic studies aiming at improving abiotic stress tolerance in wheat.  相似文献   

Evaluation of several selection procedures for predicting yield performance of progenies in two populations of cotton (Gossypium barbadense L.)     

Mohamed A. Siddig 《Euphytica》1967,16(3):377-384

Average, combined and specific indices involving lint yield and its components “seeds per boll” and “lint per seed” were computed for two populations of cotton (Gossypium barbadense) evaluated in two seasons. All indices were constructed to maximize advance in “lint yield”. Indices were evaluated as to their usefulness in identifying high yielding genotypes. Within the limits of this experiment it was shown that:

1. 1.
   Specific indices were superior to yield as criteria for selection in both predicted and actual gains.  相似文献