scholarly journals COMBINING ABILITY FOR GRAIN YIELD AND SOME AGRONOMIC TRAITS IN DIALLEL CROSSES OF BREAD WHEAT UNDER NITROGEN STRESSED CONDITIONS

2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
yassmin mohamed
Author(s):  
Soleman M. Al-Otayk

The present study was carried out to evaluate agronomic traits and assessment of genetic variability of some wheat genotypes at Qassim region, Saudi Arabia', during 2010/11 and2011/12 seasons. Fourteen wheat genotypes including five bread wheat and nine durum wheat genotypes were evaluated in randomized complete block design with three replications. The genotypes were evaluated for ten different yield contributing characters viz., days to heading, days to maturity, grain filling period, grain filling rate, plant height, number of spikes m-2, kernels spike-1, 1000-kernel weight, grain yield and straw yield. The combined analysis of variance indicated the presence of significant differences between years for most characters. The genotypes exhibited significant variation for all the characters studied indicating considerable amount of variation among genotypes for each character. Maximum coefficient of variation was observed for number of spikes m-2 (17%), while minimum value was found for days to maturity. Four genotypes produced maximum grain yield and statistically similar, out of them two bread wheat genotypes (AC-3 and SD12) and the other two were durum wheat (AC-5 and BS-1). The genotypes AC-3, AC-5 and BS-1 had higher grain yield and stable in performance across seasons. The estimation of phenotypic coefficient of variation in all the traits studied was greater than those of the genotypic coefficient of variation. High heritability estimates (> 0.5) were observed for days to heading, days to maturity, and plant height, while the other characters recorded low to moderate heritability. The high GA % for plant height and days to heading (day) was accompanied by high heritability estimates, which indicated that heritability is mainly due to genetic variance. Comparatively high expected genetic advances were observed for grain yield components such as number of kernels spike-1 and 1000-kernel weight. Grain yield had the low heritability estimate with a relatively intermediate value for expected genetic advance. The results of principle component analysis (PCA) indicated that the superior durum wheat genotypes for grain yield in the two seasons (AC-5 and BS-1) are clustered in group II (Fig. 2). Also, the superior two bread wheat genotypes (AC-3 and SD12) were in group I. Therefore, it could be future breeding program to develop new high yielding genotypes in bread and durum wheat.


1968 ◽  
Vol 10 (2) ◽  
pp. 460-469 ◽  
Author(s):  
George H. L. Liang ◽  
E. G. Heyne ◽  
J. H. Chung ◽  
Y. O. Koh

Analysis of a six-variety diallel indicates that both general and specific combining ability were important for anthesis time and that specific combining ability seems more important for grain yield. Significant interactions were observed between general combining ability and locations for yield, anthesis time, and protein content while significant interaction between specific combining ability and locations was observed for protein content only.For grain yield, overdominance was indicated by the (H1/D)½ ratio; at least four groups of genes were involved in controlling yield. Heritability estimate was slow. For anthesis time, a partial dominance was indicated. Approximately three groups of genes controlled anthesis; heritability estimate was high. For protein content, a partial dominance was noted. Two groups of genes were estimated for control of protein content; heritability estimate was intermediate.The regression coefficients for the three characters were less than 1, but only that for protein content was significantly so. The deviation of the regression line from unit slope may indicate the ptesence of either epistasis or correlated gene distribution or both in the materials tested.


2019 ◽  
Vol 48 (1) ◽  
pp. 85-93
Author(s):  
Vijay Sharma ◽  
NS Dodiya ◽  
RB Dubey ◽  
Rumana Khan

Pooled analysis of 8 genotypes of wheat of diverse origin, their 28 F1s and 2 checks was carried out in 4 different environments to study the combining ability in bread wheat for grain yield and its component traits. On pooled basis, analysis of variance due to GCA and SCA was significant for all characters revealed difference between parents for GCA and difference between crosses for SCA. Similarly, mean square due to GCA × E was significant for number of effective tillers per plant and flag leaf area revealed influence of environment on GCA. Whereas SCA × E was also significant for number of effective tillers per plant and grain yield per plant revealed influence of environment on SCA. The variance due to GCA was higher than their respective SCA for all characters except number of grains per spike indicating that additive type of gene action played role in the expression of all these traits. Significant GCA effects for grain yield and its component traits were exhibited by the parents HD 2987, Lok 1 and HI 1544. Fourteen crosses recorded showed significant SCA effects for grain yield and related traits.


2021 ◽  
Vol 4 (3) ◽  
pp. 286-304
Author(s):  
Lemi Mideksa Yadesa ◽  
Sentayehu Alamerew ◽  
Berhanu Tadesse

In spite of the importance of quality protein maize to alleviate protein deficiency, almost all maize varieties cultivated in Ethiopia are normal maize varieties, which are devoid of lysine and tryptophan. Perusing the combining ability of QPM inbred for grain yield and its components is vital to design appropriate breeding strategies for the development of nutritionally enhanced maize cultivars. A line x tester analysis involving 36 crosses generated by crossing 9  elite maize inbred lines with 4 testers were evaluated for different desirable agronomic traits during the 2019 main season at BNMRC and JARC. The experiment was conducted using alpha lattice design with 3 replications. The objectives were to determine the combining ability of quality protein maize inbred lines, adapted to mid altitude agroecology of Ethiopia for agronomic traits. The crosses were evaluated in alpha lattice design replicated 3 times. Analyses of variances showed significant mean squares due to crosses for almost all the traits studied. GCA mean squares due to lines and testers were significant (P<0.05 or P<0.01) for most studied traits. SCA mean squares were also significant for most attributes across locations. The comparative importance of GCA and SCA variances observed in the current study for most studied traits indicated the preponderance of additive genetic variance in governing these attributes. Only L3 was the best general combiner for grain yield. Inbred line L3, for days to anthesis and L5 for days to silking had negative and significant GCA effects. L5 and L6 displayed negative and significant GCA effects for plant and ear height. Crosses, L2xT4, L3xT4, L4xT4, L5xT2, L6xT3, L7xT2, L9xT1 and L9xT4 were good specific combiners for grain yield. In general, these genotypes help as a source of promising alleles that could be used for forthcoming breeding work in the development of quality protein maize cultivars with desirable traits.


2014 ◽  
Vol 69 (1) ◽  
pp. 44-54
Author(s):  
NASER SABAGHNIA ◽  
MOHSEN JANMOHAMMADI ◽  
ADEL BASHIRI ◽  
REZA ASGHARI-SHIRGHAN

The genetic diversity among 56 bread wheat (Triticum aestivum L.) genotypes was evaluated by 18 agronomical traits in the experimental field at Maragheh, Iran. Significant differences among bread wheat genotypes in all of the measured traits i.e. stem diameter, plant height, leaf number, leaf length, leaf width, tiller number, internode length, peduncle length, spike length, floret number, spikelet number, grain number, length of awn, grain diameter, grain length, the number of days to flowering, thousand seed weight and grain yield. The coefficient of variation (CV) was high for grain yield (25.61%), number of tillers per plant (22.06%) and number of grains per spike (21.45). The other remaining traits recorded moderate to low CV estimates from 14.30% in grain number per spike to 4.81% in days to flowering. The largest thousand seed weight was 45.93 g, the lowest thousand seed weight was 26.16 g and the mean thousand seed weight was 37.85 g. The mean performance of grain yield was 5031.2 kg ha-1, the minimum grain yield was 2835.0 kg ha-1 and the maximum grain yield was 7125.3 kg ha-1. Ward’s minimum variance cluster analysis based on squared Euclidian distance on the raw data of 18 agronomic traits clearly separated five clusters. In general, cluster analysis of the 56 genotypes based on the selected agronomic traits was consistent with known information. Our plant materials could be important germplasm resources for enriching the genetic background of commercial cultivars. Such genetic differences of bread wheat traits studied in this investigation can be applied as a new source of variation in other breeding programs and crossing nurseries in breeding program


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