Home About us Contact
|
Home About us Contact | ||
|
|
||
Substitution Lines (substitution + line)
Selected AbstractsIntrogression of Resistance to Powdery Mildew Conferred by Chromosome 2R by Crossing Wheat Nullisomic 2D with RyeJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 7 2006Diao-Guo An Abstract Using the nullisomic back-cross procedure, four wheat-rye chromosome substitution 2R (2D) lines with different agronomic performance, designated WR02-145-1, WR01-145-2, WR02-145-3, and WR02-145-4, were produced from a cross between 2D nullisomic wheat (Triticum aestivum L. cv. "Xiaoyan 6") and rye (Secale cereale L. cv. "German White"). The chromosomal constitution of 2n=42=21 in WR02-145 lines was confirmed by cytological and molecular cytogenetic methods. Using genomic in situ hybridization on root tip chromosome preparations, a pair of intact rye chromosomes was detected in the WR02-145 lines. PCR using chromosome-specific primers confirmed the presence of 2R chromosomes of rye in these wheat-rye lines, indicating that WR02-145 lines are disomic chromosome substitution lines 2R(2D). The WR02-145 lines are resistant to the powdery mildew (Erysiphe graminis DC. f. sp. tritici E. Marchal) isolates prevalent in northern China and may possess gene(s) for resistance to powdery mildew, which differ from the previously identified Pm7 gene located on chromosome 2RL. The newly developed "Xiaoyan 6"- "German White" 2R (2D) chromosome substitution lines are genetically stable, show desirable agronomic traits, and are expected to be useful in wheat improvement. (Managing editor: Li-Hui Zhao) [source] Plant survival after freezing in wheat ,Cappelle Desprez' (,Bezostaya 1') intervarietal chromosome substitution linesPLANT BREEDING, Issue 2 2008G. Ganeva Abstract The effect of individual chromosomes of the wheat variety ,Bezostaya 1' on plant resistance to low temperatures was studied using the available set of intervarietal ,Cappelle Desprez' (,Bezostaya 1') chromosome substitution lines. The number of plants surviving after freezing at ,12, ,15 and ,17°C was determined for both parents and lines in trials in 2004/2005 and 2005/2006. Significant differences between the three temperature treatments and between lines were found, implying that two factors, the level of temperature stress and chromosome substitutions, were influencing plant survival. Improved frost resistance in both trials was associated with genes located on five chromosomes: 5A, 2D, 4A, 5D and 6A. An increase in the plant frost resistance because of the effects of 7A and 1A chromosomes was also observed in the 2005/2006 trial, when the overall autumn and winter (January) temperatures were lower than in 2004/2005. [source] Identification of wheat,Thinopyrum intermedium 2Ai-2 ditelosomic addition and substitution lines with resistance to barley yellow dwarf virusPLANT BREEDING, Issue 2 2006Z. S. Lin Abstract Among the regenerated plants derived from immature hybrid embryos of wheat,Thinopyrum intermedium disomic addition line Z6 × common wheat variety ,Zhong8601', a plant with a telocentric chromosome and barley yellow dwarf virus (BYDV) resistance was obtained. The telocentric chromosome paired with an entire Thinopyrum chromosome to form a heteromorphic bivalent at meiotic metaphase I. Genomic in situ hybridization showed that the telosome originated from Th. intermedium. Two ditelosomic additions and one disomic substitution were identified among the offspring of the plant. Two random amplified polymorphic DNA molecular markers were identified among 150 random primers used to detect the different arms of the alien chromosome. These might be useful for developing translocation lines with BYDV resistance. [source] Inheritance of resistance of wheat to eyespot at the adult stagePLANT BREEDING, Issue 6 2002H. Muranty Abstract Moderate resistance to eyespot was first incorporated in the variety Cappelle-Desprez (CD). Later the gene Pch1, which could confer a higher level of resistance, was introduced from Aegilops ventricosa. However Pch1 -carrying varieties can sustain significant eyespot-induced yield losses in severe attack situations. A strategy to further enhance the resistance of wheat is by pyramiding Pch1 and the genes for resistance in CD. The first requirement to achieve this is a better understanding of the genetics of resistance in CD. The resistance of the 21 Cappelle-Desprez (Bezostaya) disomic substitution lines was evaluated. Chromosome 7A was confirmed as carrying a major gene for resistance to eyespot at the seedling stage. However, this study demonstrates that this chromosome has no effects at the adult stage. Chromosome 5A was shown to carry a major gene for resistance to eyespot at the adult stage, which was stably expressed each year of testing. Chromosomes 1A and 2B had significant effects for only two years among four. [source] Chromosomal location of Fusarium head blight resistance genes and analysis of the relationship between resistance to head blight and brown foot rotPLANT BREEDING, Issue 1 2000A. Mentewab Abstract In order to identify chromosomes involved in resistance to Fusarium head blight, a set of 21 substitution lines of Triticum macha (resistant) chromosomes into ,Hobbit''sib'(susceptible) were evaluated in trials over 2 years. For the first year's trial, all plants were inoculated on the same day with a conidial suspension of F. culmorum. For the second trial, individual plants were inoculated precisely at mid anthesis of each plant over a period of 2 weeks. The disease level was assessed by visual scoring, relative ear weight and F. culmorumn -specfic quantitative polymerase chain reaction. The results showed that T. macha chromosomes 1B, 4A and 7A conferred good overall resistance, suggesting that they carry important genes for resistance. In two additional trials, T. macha and ,Hobbit''sib' were evaluated for resistance to brown foot rot. The results showed that T. macha was more susceptible than ,Hobbit',sib', indicating that stem base disease response is not correlated with head blight resistance in these cultivars. [source] | ||||||||||