CHOOSING THE BEST PARENTS FOR A BREEDING PROGRAM FROM AMONG EIGHT OAT CULTIVARS CROSSED IN DIALLEL

1976 ◽  
Vol 56 (2) ◽  
pp. 263-274 ◽  
Author(s):  
D. R. SAMPSON

Twenty-eight oat hybrids from a diallel cross of eight parents were evaluated using field-grown F2 (1970) and F3 (1971) bulks at competitive spacing and with different exposures to moisture stress. These were compared with irrigated, space-planted F1’s. Short, stout straw was negatively correlated with grain yield. Correlations of 1,000-kernel weight and panicle number with other traits changed sharply from year to year. General combining ability (GCA) effects showed that Astro, Clintford and Purdue 6316 were outstanding parents for desirable stem type, as were Gemini and Clintford for 1,000-kernel weight and Gemini, Kelsey and Marino for yield. Index selection among the progenies using four traits gave largely contradictory results for the 2 yr, but GCA effects of the index values point to Astro and Clintford as the best all-round parents. Data from F1 spaced plants in an optimum environment were useful for predicting field responses in the year when no moisture stress occurred during grain filling, but not in the year with such stress. Midparent values for grain yield were highly correlated with progenies’ yields only in the year with no moisture stress during grain filling.

1974 ◽  
Vol 10 (4) ◽  
pp. 241-245 ◽  
Author(s):  
K. P. Sinolinding ◽  
A. Rehman Chowdhry

SUMMARYAnalysis of a 4-parent diallel cross showed marked heterosis for yield and its components in two crosses (Mexipak × Dirk and C273 × AU49) under irrigation, while little or negative heterosis occurred under moisture stress. A large part of the genetic variation among crosses for yield, and most components of yield, was attributed to the general combining ability, indicating that the additive effects were important. Reciprocal effects and various interactions were insignificant except for kernel weight, which suggests that effective selection could be made under irrigation of genotypes adaptable to moisture stress.


1976 ◽  
Vol 86 (3) ◽  
pp. 537-542 ◽  
Author(s):  
H. G. Nasr ◽  
W. Khayrallah

SummaryThe F1 and F2 generations of a diallel cross of six-row barley involving the parents, Beecher, Athenais, Atlas 46, 3130-4564-3, and 3130-864-4 were studied and heterosis, inbreeding depression, and combining abilities were measured for grain yield, number of tillers per plant, number of kernels per plant, kernel weight, and plant height. Significant heterosis was detected for grain yield in two of the ten crosses, for number of tillers per plant in one cross, for number of kernels per plant in two crosses, for plant height in three crosses, and for kernel weight in none of the crosses. The inbreeding depression of the F2 generation was present in most cases but significantly so in a few. Atlas 46 x 3130-4564-3 exhibited inbreeding depression for grain yield, number of kernels per plant, and plant height.The general combining ability (GCA) mean squares of both generations were significant for all characters studied except number of kernels per plant in the F1 generation. The specific combining ability (SCA) mean squares were significant for only plant height in the F1 generation and all characters studied except number of tillers per plant in the F2 generation.The GCA effects indicated that Beecher and Athenais are good general combiners for grain yield and its components. The latter parent produced good yielding hybrids with slightly shorter plants than the remaining hybrids.The SCA effects revealed that Athenais × 3130-4564-3, Athenais × 3130-864-4, and Beecher × Atlas 46 seem good specific combinations for high grain yield. Also, the former two crosses tend to produce shorter plants.


Author(s):  
Amrita Kumari ◽  
R. D. Ranjan ◽  
Chandan Roy ◽  
Awadesh Kumar Pal ◽  
S. Kumar

Heat stress, particularly the stress appears at the time of flowering to grain filling stages causing severe yield loss in wheat. Heat tolerance is complex phenomena that include adjustment in morphological, physiological and biochemical traits of the crop. Present investigation was carried out to understand the effect of terminal heat stress on different traits of wheat. The experiment was conducted in three dates of sowing as timely sown, late sown and very late sown to expose the crop to heat stress at later stages of the crop growth. Significant genetic variations for all the traits evaluated under three conditions indicated the presence of variability for the traits. Trait association analysis revealed that flag leaf chlorophyll content and MSI at seedling stage; MDA at reproductive stage had direct relationship with grain yield. While under very late sown condition MDA and RWC at seedling stages were found to be highly correlated with grain yield. It indicates that MDA, RWC at seedling stage and days to booting, days to milking plays important role in very late sown condition that can be used as selection criteria in breeding programme.


2019 ◽  
Vol 20 (20) ◽  
pp. 5241 ◽  
Author(s):  
Kiyoon Kang ◽  
Yejin Shim ◽  
Eunji Gi ◽  
Gynheung An ◽  
Nam-Chon Paek

Exploring genetic methods to improve yield in grain crops such as rice (Oryza sativa) is essential to help meet the needs of the increasing population. Here, we report that rice ONAC096 affects grain yield by regulating leaf senescence and panicle number. ONAC096 expression increased rapidly in rice leaves upon the initiation of aging- and dark-induced senescence. Two independent T-DNA insertion mutants (onac096-1 and onac096-2) with downregulated ONAC096 expression retained their green leaf color during natural senescence in the field, thus extending their photosynthetic capacity. Reverse-transcription quantitative PCR analysis showed that ONAC096 upregulated genes controlling chlorophyll degradation and leaf senescence. Repressed OsCKX2 (encoding cytokinin oxidase/dehydrogenase) expression in the onac096 mutants led to a 15% increase in panicle number without affecting grain weight or fertility. ONAC096 mediates abscisic acid (ABA)-induced leaf senescence by upregulating the ABA signaling genes ABA INSENSITIVE5 and ENHANCED EM LEVEL. The onac096 mutants showed a 16% increase in grain yield, highlighting the potential for using this gene to increase grain production.


2003 ◽  
Vol 83 (2) ◽  
pp. 275-281 ◽  
Author(s):  
P. E. Juskiw ◽  
J. H. Helm

Seeding date is an important factor influencing productivity of barley (Hordeum vulgare L.). When conditions are conducive to early seeding or result in delayed seeding, producers need to know how cultivars will respond to these seeding situations. In this study, five cultivars (Abee, Harrington, Jackson, Noble and Virden) registered for western Canada were studied for 4 yr (1990 to 1993) when seeded early (late April or early May), in mid-May, in late-May, or late (mid-June) at Lacombe, AB. For all cultivars, early seeding resulted in grain yield advantages of 113 to 134% of the mean site yield, while with late seeding, grain yields were reduced to 54 to 76% of the mean site yield. The reduction in yield was least for Jackson, the earliest maturing cultivar tested. Late seeding reduced the period from sowing to emergence, vegetative period, grain-filling period, time from emergence to physiological maturity, test weight, grain yield, kernel weight, and tillers per plant; and increased plant height and percent thins. Late seeding had no significant effect on phyllochron, stand establishment, scald, lodging, protein content of the grain, kernel number per spike, and spikelet number per spike. Barley responded positively to early seeding in central Alberta, but when seeding was delayed (in this study to mid-June) the early and mid-maturing six-rowed cultivars with short phyllochrons performed better than the two-rowed and late six-rowed cultivars. Key words: Hordeum vulgare L., seeding rate, phenological development, grain quality, grain yield, components


2021 ◽  
Vol 22 (1) ◽  
pp. 1
Author(s):  
Nurwulan Agustiani ◽  
Sujinah Sujinah ◽  
Indrastuti Apri Rumanti

<p class="abstrakinggris"><span lang="EN-US">Stagnant flooding (SF) stress has contributed decreasing rice production in Indonesia. The study aimed to explore critical variables of rice growth that contribute to the decreasing grain yield under SF conditions and a common irrigation system (control). The experiment was arranged in a complete randomized block design with four replications to test 10 rice genotypes (Inpari 30 Ciherang Sub-1, Inpara 3, Inpara 4, Inpara 8, IRRI119, IRRI154, IR42, IR14D121, IR14D157, and Tapus). The water depth was managed according to the farmer’s practices for control, while for SF plots the standing water depth was gradually increased from 35 days after transplanting and was maintained at 50 cm until harvest. Results showed that plant height, tillering ability, leaf greenness, panicle number per hill and grain filling percentage were critical growth variables that affect grain yield at optimal conditions. The yield of the 10 genotypes decreased by 25–50% under SF conditions. Inpara 3 had the stable yield in those two watering conditions. Therefore, it could be used as a check variety for SF condition. Inpara 9 and IRRI119 experienced decreased yield of more than 50% under SF conditions. The key factors determining the decreased yield were tillering ability and green leaf level. Optimization of the two variables at SF conditions will largely determine rice yield associated with panicle number per hill and grain number per panicle. Results of the study are useful as preliminary recommendations for designing new variety and cultivation techniques to reduce the impact of SF stress on rice yield.</span></p>


Biology ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Cong Zhang ◽  
Bangyou Zheng ◽  
Yong He

Improving plant net photosynthetic rates and accelerating water-soluble carbohydrate accumulation play an important role in increasing the carbon sources for yield formation of wheat (Triticum aestivum L.). Understanding and quantify the contribution of these traits to grain yield can provide a pathway towards increasing the yield potential of wheat. The objective of this study was to identify kernel weight gap for improving grain yield in 15 winter wheat genotypes grown in Shandong Province, China. A cluster analysis was conducted to classify the 15 wheat genotypes into high yielding (HY) and low yielding (LY) groups based on their performance in grain yield, harvest index, photosynthetic rate, kernels per square meter, and spikes per square meter from two years of field testing. While the grain yield was significantly higher in the HY group, its thousand kernel weight (TKW) was 8.8% lower than that of the LY group (p < 0.05). A structural equation model revealed that 83% of the total variation in grain yield for the HY group could be mainly explained by TKW, the flag leaf photosynthesis rate at the grain filling stage (Pn75), and flag leaf water-soluble carbohydrate content (WSC) at grain filling stage. Their effect values on yield were 0.579, 0.759, and 0.444, respectively. Our results suggest that increase of flag leaf photosynthesis and WSC could improve the TKW, and thus benefit for developing high yielding wheat cultivars.


2015 ◽  
Vol 36 (4) ◽  
Author(s):  
K. John ◽  
P. Raghava Reddy

Hybridization followed by selection in segregating generations is the main mode of varietal development in self-pollinated crops like groundnut. Before making crosses, it is important to know which of the parents are going to nick well and yield desirable segregants in terms of yield and other desirable attributes aimed at. There are different mating designs to identify the parents to be included in hybridization programmes. One of the widely used and most informative one is diallel mating design. After identification of parents more suitable to be involved in breeding programme, it is necessary to know the mode of inheritance of the traits to be improved to make wise choice of selection approaches to be followed in segregating generations. Therefore the breeder is constantly needing to determine the potential of additional germplasm as parents, Earlier studies suggest the importance of additive general combining ability (GCA) and non additive (specific combining ability and heterosis) genetic effects in evaluating hybrid performance among parental groundnut lines. The prominent effects on crop plants are reduction in plant growth and changes in various physiological processes. Moisture stress can also adversely influence yield attributes like number of mature pods per plant, 100-pod weight, 100-kernel weight, shelling per cent and harvest index.


1968 ◽  
Vol 48 (3) ◽  
pp. 313-320 ◽  
Author(s):  
C. A. Campbell

Two series of moisture treatments were used to determine if there was a specific growth stage at which low soil moisture stress caused poor seed set in Chinook wheat, and also to determine whether grain yield could be maximized by manipulating time of increasing or decreasing moisture stress.Maintaining soil moisture at 25 to 10% (dry) until the shot-blade stage produced 80% seed set, compared with only 30% seed set when moisture was maintained at 25% to 16% (wet) during the same period. Increasing or decreasing the soil moisture stress at different growth stages had little effect on the number of florets per head or the mean kernel weight. Under the conditions of this experiment, the number of heads and percent seed set were the main components influencing grain yield. The highest grain yields were obtained when plants were grown under dry conditions until late shot-blade and under wet conditions thereafter. Conversely, minimum grain yields were realized where plants were grown under wet conditions until late shot-blade and under dry conditions thereafter. Straw yield was closely related to the total moisture used.


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