scholarly journals Phenotyping and Identification of Reduced Height (Rht) Alleles (Rht-B1b and Rht-D1b) in a Nepali Spring Wheat (Triticum aestivum L.) Diversity Panel to Enable Seedling Vigor Selection

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2412
Author(s):  
Kamal Khadka ◽  
Mina Kaviani ◽  
Manish N. Raizada ◽  
Alireza Navabi

Nepal is facing more intense early-season drought stress associated with climate change. The introgression of reduced height (Rht) alleles to enable stem dwarfism in bread wheat (Triticum aestivum L.) inadvertently reduced coleoptile length and growth plasticity in seedlings, making improved varieties less suitable for deep seeding; these alleles may have also reduced seedling root length. Therefore, with the long-term objective of breeding wheat for early-season drought stress, a Nepali spring wheat panel was evaluated to assess allelic variation at the most common dwarfing-associated loci (Rht-B1, Rht-D1) and their impact on coleoptile/seedling root traits, and to identify accessions with longer and/or more GA-responsive coleoptiles as parents for future breeding. Here, Kompetitive Allele Specific PCR (KASP) was used to genotype accessions. The panel was phenotyped using the cigar-roll method in the presence/absence of GA3. Plant height was measured under field conditions. The results showed that Nepali landraces had a significantly higher frequency of the non-dwarfing allele Rht-B1a. The dwarfing alleles Rht-B1b and Rht-D1b had negative effects on coleoptile length but positive effects on the length of the longest seedling root. However, 40 potential semi-dwarf accessions (possessing Rht-B1b and/or Rht-D1b alleles) with long and/or more plastic coleoptiles suited for deep sowing were identified. This included 12 accessions that exhibited significant changes in coleoptile length in response to GA3 treatment.

2021 ◽  
pp. 1-10
Author(s):  
Chang Liu ◽  
Rehana S. Parveen ◽  
Samuel R. Revolinski ◽  
Kimberly A. Garland Campbell ◽  
Michael O. Pumphrey ◽  
...  

Abstract Genetic susceptibility to late maturity alpha-amylase (LMA) in wheat (Triticum aestivum L.) results in increased alpha-amylase activity in mature grain when cool conditions occur during late grain maturation. Farmers are forced to sell wheat grain with elevated alpha-amylase at a discount because it has an increased risk of poor end-product quality. This problem can result from either LMA or preharvest sprouting, grain germination on the mother plant when rain occurs before harvest. Whereas preharvest sprouting is a well-understood problem, little is known about the risk LMA poses to North American wheat crops. To examine this, LMA susceptibility was characterized in a panel of 251 North American hard spring wheat lines, representing ten geographical areas. It appears that there is substantial LMA susceptibility in North American wheat since only 27% of the lines showed reproducible LMA resistance following cold-induction experiments. A preliminary genome-wide association study detected six significant marker-trait associations. LMA in North American wheat may result from genetic mechanisms similar to those previously observed in Australian and International Maize and Wheat Improvement Center (CIMMYT) germplasm since two of the detected QTLs, QLMA.wsu.7B and QLMA.wsu.6B, co-localized with previously reported loci. The Reduced height (Rht) loci also influenced LMA. Elevated alpha-amylase levels were significantly associated with the presence of both wild-type and tall height, rht-B1a and rht-D1a, loci in both cold-treated and untreated samples.


2019 ◽  
Vol 17 (2) ◽  
pp. 148-152
Author(s):  
Md. Anowarul Haque

The Rht-B1 locus on the short arm of chromosome 4B has multiple alleles that give phenotypic expressions ranging from semi-dwarfism to extreme dwarfism. Allelic variation at Rht-B1 locus was also found in semi-dwarf Triticum polonicum L. cv. IC12196. The semi-dwarf allele from IC12196 could be an alternative source of reduced height gene. The experimental lines derived from the cross between Triticum aestivum L. cv. Novosibirskaya 67 (N67) and IC12196 were analyzed concerning the introgression of semi-dwarf allele from IC12196. The aim of the present study was to assess the selection for the semi-dwarfism and recombination around the locus of semi-dwarf gene using microsatellite markers on the short arm of chromosome 4B. The Rht-IC12196 allele was allelic to Rht-B1b allele, and microsatellite markers indicated that the Rht-IC12196 allele was linked with the markers, Xbarc1045 and Xgwm113 on the short arm of chromosome 4B. Out of 112 hexaploid introgression lines, 29 lines were semi-dwarf. The Xgwm113 and Xhbg226 markers flanking the Rht-B1 locus were replaced by N67 allele in the majority of introgression lines. Although it did not intend, the region around the Rht-B1 locus was highly selectable, but on short arms of chromosome 4B, Rht-IC12196 gene near the locus Xgwm113 explained a large part of the phenotypic variation originated from N67-allele and non-parental allele in tall accessions. The Rht-B1a allele was favorable in the consequence of bulk population breeding and the frequency of Rht-B1a allele was 73% in the hexaploid introgression lines. J. Bangladesh Agril. Univ. 17(2): 148–152, June 2019


1990 ◽  
Vol 70 (1) ◽  
pp. 299-302 ◽  
Author(s):  
R. J. GRAF ◽  
P. HUCL ◽  
J. SMITH ◽  
L. S. P. SONG

Oslo red spring wheat (Triticum aestivum L.) is a mid-season, semidwarf wheat with intermediate yield potential, eligible for grades of Canada Prairie Spring. Oslo performs best in the black soil zone; it is not well adapted to areas prone to pre-anthesis drought stress. Breeder seed of Oslo will be maintained by Saskatchewan Wheat Pool Product Development, Watrous, Saskatchewan.Key words: Triticum aestivum, wheat (spring), high yielding, cultivar description


2019 ◽  
Vol 132 (11) ◽  
pp. 3023-3033 ◽  
Author(s):  
Firdissa E. Bokore ◽  
Richard D. Cuthbert ◽  
Ron E. Knox ◽  
Arti Singh ◽  
Heather L. Campbell ◽  
...  

1991 ◽  
Vol 71 (2) ◽  
pp. 519-522 ◽  
Author(s):  
R. M. DePauw ◽  
K. R. Preston ◽  
T. F. Townley-Smith ◽  
E. A. Hurd ◽  
G. E. McCrystal ◽  
...  

Biggar red spring wheat (Triticum aestivum L.) combines high grain yield potential with semidwarf stature and wide adaptation. Biggar has improved end-use suitability relative to HY320 such as harder kernels, better flour milling properties, greater water absorption, and stronger gluten properties. It received registration No. 3089 and is eligible for grades of Canada Prairie Spring (red). Key words: Triticum aestivum, wheat (spring), high yield, cultivar description


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