scholarly journals Evaluation of reciprocal cross populations for spike-related traits in early consecutive generations of bread wheat (Triticum aestivum L.)

Genetika ◽  
2017 ◽  
Vol 49 (2) ◽  
pp. 511-528
Author(s):  
Imren Kutlu ◽  
Alpay Balkan ◽  
Kayıhan Korkut ◽  
Oguz Bilgin ◽  
Ismet Baser

Breeding effort on increasing grain yield of wheat will incessantly continue because it is indispensable product. Obtaining the genetic information such as genotypic variation, heritability, genetic advance is the fundamental components of these studies. It is important that the maternal effects are put forward throughout successive generations because of genotypic and/or environmental effects as far as variation. This research was conducted to investigate changes of reciprocal crosses throughout successive generations and determine selection criteria for high yield in early generations. For this purpose, the populations were analyzed with regard to genotypic and phenotypic variation coefficient, heritability, genetic advance and Unweighted Pair Group Method (UPGMA) cluster analysis for real crosses, reciprocals and all genotypes separately. According to the results, heritability and genetic advance values of traits investigated were highly varied throughout successive generations among real crosses, reciprocals and all genotypes. This finding indicated that non-additive gen effects or epitasis played a role in inheritance of all traits. Dissimilarity of crosses than their reciprocals indicated variation of successive generation. Dissimilarity value of each parent differed as generation progresses according to combination created. This condition suggested that there were maternal effects in this population throughout successive generations. Grain weight per spike, spike harvest index and spike density had high direct and indirect effects on the grain yield at all of three generations, it proved that these traits can be a selection criterion for early generations. Sana was the best parent and ?Bezostaja x Krasunia? and ?Krasunia x Pehlivan? were best performance in most of traits at all generations.

Author(s):  
Ahmed Medhat Mohamed Al-Naggar ◽  
Mohamed Abd El-Maboud Abd El-Shafi ◽  
Mohamed Helmy El-Shal ◽  
Ali Hassan Anany

Strong correlations between wheat traits and drought tolerance (DT) associated with high heritability and high genetic advance from selection would allow plant breeder to use such traits as selection criteria. The objective of the present investigation was to determine the optimum selection criteria and selection environment for drought tolerance via estimation of correlation coefficients (r) among 13 agronomic, grain yield and quality traits and DT of 20 wheat landraces, broad-sense heritability (h2b) and genetic advance (GA) from selection for such traits under well-watered (WW) and water stressed (WS) environments. A two-year experiment was carried out using a split-plot design with four replications. Results concluded that the best selection criterion for drought tolerance in our study was grain yield/plant (GYPP), followed by a number of grains/spike (GPS), grain filling period (GFP), grain starch (GSC) and protein (GPC) content, plant height (PH) and days to maturity (DTM), since they showed high (r), high h2b and high GA estimates. The best selection environment was WW for days to anthesis, PH, spikes/plant, GPS, spikelets/spike, GYPP, GPC and WS for DTM, GFP, GSC and thousand-grain weight traits. This information could help future breeding programs in selection for improving drought tolerance of wheat.


Author(s):  
A. M. M. Al-Naggar ◽  
R. M. Abd El-Salam ◽  
M. R. A. Hovny ◽  
Walaa Y. S. Yaseen

Information on heritability and trait association in crops assist breeders to allocate resources necessary to effectively select for desired traits and to achieve maximum genetic gain with little time and resources. The objectives of this investigation were to determine the amount of genetic variability, heritability, genetic advance and strength of association of yield related traits among sorghum lines under different environments in Egypt. Six environments with 25 sorghum B-lines were at two locations in Egypt (Giza and Shandaweel) in two years and two planting dates in one location (Giza). A randomized complete block design was used in each environment with three replications. Significant variation was observed among sorghum lines for all studied traits in all environments. Across environments, grain yield/plant (GYPP) showed positive and significant correlations with number of grains/plant (r = 0.71), days to flowering (r = 0.47), 1000-grain weight (r = 0.16) and plant height (PH) (r = 0.19). In general, the estimates of phenotypic coefficient of variation (PCV) were higher than genotypic coefficient of variation (GCV). Combined across the six environments, the highest PCV and GCV was shown by PH trait (95.14 and 43.57%) followed by GYPP (36.42 and 30.78%), respectively, indicating that selection for high values of these traits of sorghum would be effective. GYPP and PH traits showed high heritability associated with high genetic advance from selection, indicating that there are good opportunities to get success in improvement of these traits via selection procedures. Results concluded that PH is good selection criterion for GYPP and therefore selection for tall sorghum plants would increase grain yield.


2000 ◽  
Vol 80 (4) ◽  
pp. 739-745 ◽  
Author(s):  
B. L. Duggan ◽  
D. R. Domitruk ◽  
D. B. Fowler

Crops produced in the semiarid environment of western Canada are subjected to variable and unpredictable periods of drought stress. The objective of this study was to determine the inter-relationships among yield components and grain yield of winter wheat (Triticum aestivum L) so that guidelines could be established for the production of cultivars with high yield potential and stability. Five hard red winter wheat genotypes were grown in 15 field trials conducted throughout Saskatchewan from 1989–1991. Although this study included genotypes with widely different yield potential and yield component arrangements, only small differences in grain yield occurred within trials under dryland conditions. High kernel number, through greater tillering, was shown to be an adaptation to low-stress conditions. The ability of winter wheat to produce large numbers of tillers was evident in the spring in all trials; however, this early season potential was not maintained due to extensive tiller die-back. Tiller die-back often meant that high yield potential genotypes became sink limiting with reduced ability to respond to subsequent improvements in growing season weather conditions. As tiller number increased under more favourable crop water conditions genetic limits in kernels spike−1 became more identified with yield potential. It is likely then, that tillering capacity per se is less important in winter wheat than the development of vigorous tillers with numerous large kernels spike−1. For example, the highest yielding genotype under dryland conditions was a breeding line, S86-808, which was able to maintain a greater sink capacity as a result of a higher number of larger kernels spike−1. It appears that without yield component compensation, a cultivar can be unresponsive to improved crop water conditions (stable) or it can have a high mean yield, but it cannot possess both characteristics. Key words: Triticum aestivum L., wheat, drought stress, kernel weight, kernel number, spike density, grain yield


1993 ◽  
Vol 33 (6) ◽  
pp. 751 ◽  
Author(s):  
DR Coventry ◽  
TG Reeves ◽  
HD Brooke ◽  
DK Cann

A 3-year study was conducted to measure the effect of sowing time and seeding rate on the development and yield of wheat (Triticum aestivum L.) grown under high-yielding conditions in north-eastern Victoria. A range of wheat cultivars with different development responses, including 'winter' types, was used in 2 experiments in each season. High grain yields for dryland wheat were measured in the first 2 seasons (1985-86), and in 1985, near-optimal water use efficiencies (>18 kg/ha. mm effective rainfall) were obtained. In the third season (1987) grain yield was limited by adverse climatic conditions-in the me- and post-anthesis period. In each season, grain yield declined with delay in sowing time. In 1985 there was a loss of 200-250 kg grain/ha for each week's delay in sowing time. In 1987, yield loss with delayed sowing was 50-110 kg grain/ha. In each season, cultivars with late or midseason maturity development gave the highest mean yields, and the use of these maturity types allowed earlier sowing, in mid April. However, with late sowing of wheat there was a trend for early maturity types to give higher yields, and so the use of 2 wheat cultivars with distinct maturity development responses to climate is recommended. If only 1 wheat cultivar is to be used, then a late maturity type is recommended. Higher wheat yields were also obtained as spike density increased, as a result of higher seeding rates. Our data suggest that in the higher rainfall region of north-eastern Victoria, a spike density of about 500 spikes/m2 is required to optimise wheat yields.


1980 ◽  
Vol 60 (4) ◽  
pp. 1141-1146 ◽  
Author(s):  
H. G. NASS

The use of harvest index as a selection criterion for grain yield in F2 populations of spring wheat (Triticum aestivum L.) grown at two population densities was investigated. Harvest index was useful in delineating yield differences between lines for both crosses. The F4 lines selected in F2 for a high harvest index yielded about 9% more per plot in 1978 than F4 lines having a low harvest index in F2. Generally, lines selected at the higher commercial seeding rate yielded more than lines selected at the lower plant density. In 1979, a heavy Fusarium infection reduced the mean grain yield of the F6 lines and suppressed any significant response to selection resulting from population density and harvest index in F2. While selection based on high harvest index at low population density can be used to select higher yielding plants it was not as effective as selection at high population density which more closely approximates commercial crop densities. Additional research is needed before the use of harvest index as a selection tool in wheat breeding programs can be recommended for use in Atlantic Canada.


2016 ◽  
Vol 69 (3) ◽  
Author(s):  
Elżbieta Harasim ◽  
Marian Wesołowski ◽  
Cezary Kwiatkowski ◽  
Paweł Harasim ◽  
Mariola Staniak ◽  
...  

<p>The aim of the present study was to determine the effect of different growth regulator rates and nitrogen fertilization levels on yield components and to evaluate their influence on winter wheat productivity. A field experiment with winter wheat ‘Muza’ was conducted at the Czesławice Experimental Farm, belonging to the University of Life Sciences in Lublin, Poland over the period 2004–2007. In this experiment, the effect of the studied factors on yield and its components was primarily dependent on weather conditions during the study period.</p><p>An increase in nitrogen rate from 100 to 150 kg ha<sup>−1</sup> in 2005 and 2007 had a significant effect on the increase in grain yield per unit area. In 2005, the grain yield rose through increased spike density (by 6.3%) and a higher number of grains per spike (by 1.6%). The 1000-grain weight decreased the grain yield per unit area (by 0.04 t ha<sup>−1</sup>). In 2007, the higher yield of wheat fertilized with nitrogen at a rate of 150 kg N ha<sup>−1</sup> was positively affected by all the three yield components. The statistical analysis of the results showed that the winter wheat grain yields were also significantly affected by the retardant rates applied depending on the year.</p>


1999 ◽  
Vol 50 (7) ◽  
pp. 1263 ◽  
Author(s):  
J. Voltas ◽  
I. Romagosa ◽  
A. Lafarga ◽  
A. P. Armesto ◽  
A. Sombrero ◽  
...  

Carbon isotope discrimination (Δ) has been found to be either positively or negatively related to grain yield of small grain cereals when grown in contrasting environments. In order to clarify a possible association between grain yield of barley (Hordeum vulgare L.) and Δ of mature kernels, five 6-rowed and five 2-rowed barley cultivars were evaluated in 22 rainfed environments of northern Mediterranean Spain. Analyses of variance suggested that the genotypic Δ values were more consistent across environments than the genotypic yields. Genotype×environment (G×E) interaction for grain yield was further explored by fitting an AMMI (additive main effects and multiplicative interaction) model. The first 2 multiplicative axes were found significant. The AMMI2 model provided more accurate estimates of genotypic yields within environments than the conventional unadjusted means across replicates. AMMI2 estimates were used for input into cluster analysis, grouping environments that ranked genotypic yields similarly. Three major groups were obtained, with average yields of 2.42 t/ha (cluster I), 3.06 t/ha (cluster II), and 5.16 t/ha (cluster III). The genotypic ranking for Δ did not vary substantially across clusters, but it changed for grain yield. The average genotypic yields in the low-yielding cluster I ranked opposite to those in the high-yielding cluster III, suggesting the existence of a crossover point at an intermediate yield level. The association between grain yield and Δ for genotypic means within clusters was variable. In cluster I, yield and Δ tended to be negatively related, whereas they were positively related in clusters II and III. Genotypes with lower Δ, i.e. with higher transpiration efficiency, performed better in low-yielding environments (mostly those grouped in cluster I). On the contrary, a high genotypic Δ was of advantage in medium (cluster II) and high-yielding environments (cluster III). This observation supports the assumption that drought tolerance and high yield potential under non-limiting growing conditions may be antagonistic concepts in barley. Genotypic means for kernel number per m 2 and Δ were consistently and positively related within clusters, suggesting that a constitutively high Δ may have been driven by a large genotypic reproductive sink. The convenience of using Δ as a selection criterion in areas exhibiting a considerable G×E interaction for grain yield is discussed.


1984 ◽  
Vol 64 (1) ◽  
pp. 113-118 ◽  
Author(s):  
I. AGUILAR-M. ◽  
L. A. HUNT

Several experiments were conducted with winter wheat (Triticum aestivum L. em. Thell.) during 1978 and 1979 to characterize genotypic variation in some physiological and morphological traits, and to evaluate the magnitude of the relationships between grain yield and the various traits studied. Straw weights of cultivars grown in Eastern Canada were similar to, and harvest indices generally lower than, those reported for high yielding varieties from other countries. Highest grain weights were also lower than the upper values recorded for some cultivars in the U.K. and Mexico, and were little affected by spikelet removal in most cases. All experiments were consistent in showing highly significant correlations between grain yield and grains per square metre, straw weight, harvest index, spikes per square metre, and flag leaf area index, and significant correlations between grain yield and grain weight. Diffusive resistance of the adaxial surface of the flag leaves differed between genotypes, but correlations between diffusive resistance and yield were low and nonsignificant in all cases, with the exception of the preanthesis period in one experiment.Key words: Wheat (winter), Triticum aestivum L. em. Thell., yield, physiological-morphological traits.


2014 ◽  
Vol 18 (2) ◽  
pp. 49-55
Author(s):  
MA Jahan ◽  
MS Hossain ◽  
M Khalekuzzaman ◽  
MM Hassan

Norin 10 based dwarfing genes (Rht1 and Rht2) have been widely exploited for increasing the grain yield in bread wheat (Triticum aestivum L.) by improving partitioning of assimilates to grain. Eight semi-dwarf wheat genotypes having either Rht1 or Rht2 dwarfing genes were compared with a tall control named, Kheri (rht) having no dwarfing genes were evaluated at Rajshahi University, Bangladesh for yield and yield contributing traits. Significant differences in grain yield and yield components were observed in genotypes under study showing the effects of dwarfing genes. Genotype Seri 82 (Rht1) and Kanchan (Rht2) had medium plant height of 75.73 and 72.22 cm respectively, highest number of tillers/plant (7.33 and 7.67), highest number of spikes/plant (6.33 and 6.67) resulted the highest grain yield per plant. Because the dwarfing genes not only provide lodging tolerance but also perhaps pleiotropically affected high yield by allowing more tillers to survive. Number of tillers/plant and number of spikes/plant showed very strong positive correlation with grain yield per plant in all the genotypes. Kheri (rht) with highest plant height (95.17cm) reduced number of tillers/plant (4.00) and spikes/plant (3.67) had the lowest grain yield per plant (3.85g). Aghrani possessed significantly the highest number of grains/spike with medium grain yield/plant (5.94g). The degree of relationship varied from genotype to genotype.DOI: http://dx.doi.org/10.3329/pa.v18i2.18075 Progress. Agric. 18(2): 49 - 55, 2007


Author(s):  
Ranjana Jaiswal ◽  
S. C. Gaur ◽  
Sunil K. Jaiswal ◽  
Anil Kumar

Problem: Wheat (Triticum aestivum L.) is one of the principal cereal crops grown worldwide and one of the important staples of nearly 2.5 billion of world population. India ranks second position in terms of both in area and production after china. The substantial improvement in production is utmost necessary to feed the growing population. Objective: In India, wheat requirement by 2030 has been estimated at 100 million metric tons and to achieve this target, wheat production can be increased either through horizontal approach i.e. by the increasing area under cultivation or through vertical approach i.e. varietal/ hybrid improvement. For effective selection and utilization of superior genotype in the germplasm lines, knowledge of genetic parameters such as genetic variability, heritability and genetic advance is essential. Materials and Methods: The experimental material comprised of ten parents, their 45 F1s and 45 F2s developed by the crossing of 10 parents viz. HUW 510, HUW 234, HUW 468, UP 2338, HD 2402, RAJ 1972, HD 2329, LOK-1, SONALIKA and K 65 in half-diallel programme to study the fourteen characters. The final trial of F1, F2 including parents was conducted during Rabi 2014-15 with three replications employing Randomized Complete Block Design at Research Farm, BRDPG College, Deoria, Uttar Pradesh, India. Result: Wider range of phenotypic coefficient of variation (PCV) was observed for all the traits in F1 generation ranged from 2.19 (days to 50% flowering) to 13.47 (leaf area index) while, genotypic coefficient of variation (GCV) ranged from 1.50 (days to 50% flowering) to 11.28 (leaf area index). High heritability was observed in both F1 and F2 generation for leaf area index and day to maturity while, moderate to low level of heritability was recorded for other characters. The high value of genetic advance was not recorded in both F1 and F2 generation. Only moderate to the low value of genetic advance was observed for all the fourteen characters under study. Conclusion: Estimate of phenotypic and genotypic coefficient of variation of fourteen characters in both generations reveals sufficient variability indicating ample scope for genetic improvement of these traits through selection. Moderate level of heritability accompanied with a moderate level of genetic advance was observed for plant height, leaf area index, days to maturity and grain yield per plant in both F1 and F2 generation indicates additive gene effect and selection may be effective.


Sign in / Sign up

Export Citation Format

Share Document