Differential responsiveness of winter and spring wheat genotypes to maize-mediated production of haploids

2004 ◽  
Vol 32 (2) ◽  
pp. 201-207 ◽  
Author(s):  
S. Singh ◽  
G. S. Sethi ◽  
H. K. Chaudhary
Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 689
Author(s):  
Yuksel Kaya

Climate change scenarios reveal that Turkey’s wheat production area is under the combined effects of heat and drought stresses. The adverse effects of climate change have just begun to be experienced in Turkey’s spring and the winter wheat zones. However, climate change is likely to affect the winter wheat zone more severely. Fortunately, there is a fast, repeatable, reliable and relatively affordable way to predict climate change effects on winter wheat (e.g., testing winter wheat in the spring wheat zone). For this purpose, 36 wheat genotypes in total, consisting of 14 spring and 22 winter types, were tested under the field conditions of the Southeastern Anatolia Region, a representative of the spring wheat zone of Turkey, during the two cropping seasons (2017–2018 and 2019–2020). Simultaneous heat (>30 °C) and drought (<40 mm) stresses occurring in May and June during both growing seasons caused drastic losses in winter wheat grain yield and its components. Declines in plant characteristics of winter wheat genotypes, compared to those of spring wheat genotypes using as a control treatment, were determined as follows: 46.3% in grain yield, 23.7% in harvest index, 30.5% in grains per spike and 19.4% in thousand kernel weight, whereas an increase of 282.2% in spike sterility occurred. On the other hand, no substantial changes were observed in plant height (10 cm longer than that of spring wheat) and on days to heading (25 days more than that of spring wheat) of winter wheat genotypes. In general, taller winter wheat genotypes tended to lodge. Meanwhile, it became impossible to avoid the combined effects of heat and drought stresses during anthesis and grain filling periods because the time to heading of winter wheat genotypes could not be shortened significantly. In conclusion, our research findings showed that many winter wheat genotypes would not successfully adapt to climate change. It was determined that specific plant characteristics such as vernalization requirement, photoperiod sensitivity, long phenological duration (lack of earliness per se) and vulnerability to diseases prevailing in the spring wheat zone, made winter wheat difficult to adapt to climate change. The most important strategic step that can be taken to overcome these challenges is that Turkey’s wheat breeding program objectives should be harmonized with the climate change scenarios.


2020 ◽  
pp. 1
Author(s):  
Khem Pant ◽  
Bishnu Ojha ◽  
Dhruba Thapa ◽  
Raju Kharel ◽  
Nutan Gautam ◽  
...  

2015 ◽  
Vol 47 (4) ◽  
pp. 49-63 ◽  
Author(s):  
A.A. Khan ◽  
M.R. Kabir

Abstract Twenty five spring wheat genotypes were evaluated for terminal heat stress tolerance in field environments in the Agro Ecological Zone-11 of Bangladesh, during 2009-2010 cropping season. The experiments were conducted at Wheat Research Centre, Bangladesh Agricultural Research Institute, using randomized block design with three replicates under non-stress (optimum sowing) and stress (late sowing) conditions. Seven selection indices for stress tolerance including mean productivity (MP), geometric mean productivity (GMP), tolerance (TOL), yield index (YI), yield stability index (YSI), stress tolerance index (STI) and stress susceptibility index (SSI) were calculated based on grain yield of wheat under optimum and late sowing conditions. The results revealed significant variations due to genotypes for all characters in two sowing conditions. Principal component analysis revealed that the first PCA explained 0.64 of the variation with MP, GMP, YI and STI. Using MP, GMP, YI and STI, the genotypes G-05 and G-22 were found to be the best genotypes with relatively high yield and suitable for both optimum and late heat stressed conditions. The indices SSI, YSI and TOL could be useful parameters in discriminating the tolerant genotypes (G-12, G-13, and G-14) that might be recommended for heat stressed conditions. It is also concluded from the present studies that biomass, grain filling rate and spikes number m-2 are suitable for selecting the best genotypes under optimum and late sowing conditions because these parameters are highly correlated with MP, GMP, YI and STI. However, high ground cover with long pre heading stage and having high grain filling rate would made a genotype tolerant to late heat to attain a high grain yield in wheat.


Agronomy ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 29 ◽  
Author(s):  
Juan Herrera ◽  
Christos Noulas ◽  
Peter Stamp ◽  
Didier Pellet

2009 ◽  
Vol 57 (4) ◽  
pp. 417-423 ◽  
Author(s):  
S. Sharma ◽  
H. Chaudhary

The success of winter × spring wheat hybridization programmes depends upon the ability of the genotypes of these two physiologically distinct ecotypes to combine well with each other. Hence the present investigation was undertaken to study the combining ability and nature of gene action for various morpho-physiological and yield-contributing traits in crosses involving winter and spring wheat genotypes. Five elite and diverse genotypes each of winter and spring wheat ecotypes and their F 1 (spring × spring, winter × winter and winter × spring) hybrids, generated in a diallel mating design excluding reciprocals, were evaluated in a random block design with three replications. Considerable variability was observed among the spring and winter wheat genotypes for all the traits under study. Furthermore, these traits were highly influenced by the winter and spring wheat genetic backgrounds, resulting in significant differences between the spring × spring, winter × winter and winter × spring wheat hybrids for some of the traits. The winter × spring wheat hybrids were observed to be the best with respect to yieldcontributing traits. On the basis of GCA effects, the spring wheat parents HPW 42, HPW 89, HW 3024, PW 552 and UP 2418 and the winter wheat parents Saptdhara, VWFW 452, W 10 and WW 24 were found to be good combiners for the majority of traits. These spring and winter wheat parents could be effectively utilized in future hybridization programmes for wheat improvement. Superior hybrid combinations for one or more traits were identified, all of which involved at least one good general combiner for one or more traits in their parentage, and can thus be exploited in successive generations to develop potential recombinants through various breeding strategies. Genetic studies revealed the preponderance of additive gene action for days to flowering, days to maturity and harvest index, and non-additive gene action for the remaining six traits.


1981 ◽  
Vol 96 (3) ◽  
pp. 623-634 ◽  
Author(s):  
Margaret A. Ford ◽  
R. B. Austin ◽  
W. J. Angus ◽  
G. C. M. Sage

SUMMARYThirty-eight spring wheat genotypes of north temperate or low latitude origin, all reasonably well adapted to the English environment, were grown in controlled environments providing the four combinations of 10 and 14 h photoperiods and temperatures of 8 and 16 °C for 6 weeks. They were then transferred to a glasshouse to assess their responses to these treatments. In separate experiments the responses of the genotypes to vernalization for 2 and 4 weeks at 2 and 8 °C were compared with unvernalized controls. The genotypes were also compared in field experiments from early, intermediate or late sowing over 3 years.Both high temperatures and long days hastened ear emergence. At the higher temperature more leaves and spikelets were produced on the main stem while in long days the plants had fewer leaves and spikelets.Most genotypes of north temperate and low latitude origin were responsive to photoperiod but not to the vernalization treatments. As a group, the low latitude ones were as responsive as the north temperate group. Five genotypes of north temperate origin were responsive to vernalization but not to photoperiod and were designated as ‘winter’ ones. Pitic 62 and Hork, from low latitudes, were responsive to vernalization and Hork was unique in also being responsive to photoperiod. The main difference between the north temperate and low latitude genotypes was in time to ear emergence and it is suggested that these differences were due to the effects of earliness genes as distinct from those determining photoperiodic response.Taking all genotypes individually there were no correlations between yield or its sensitivity to sowing date and any of the attributes measured in controlled environments. However, considering class means, the winter genotypes were the latest to reach ear emergence in the field, and their yields, while greatest from the earliest sowings, were proportionally more depressed by late sowing than the others of the north temperate origin. Thus, it may be unwise for plant breeders to incorporate a vernalization response in spring wheat varieties unless genes for ‘earliness’ are also included. The low latitude class gave only slightly lower yields than the north temperate class.It is concluded that genes other than those controlling responses to photoperiod, temperature and vernalization were more important determinants of the differences in yield among this set of genotypes.


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