Breeding for salinity resistance in mulberry (<Emphasis Type="Italic">Morus</Emphasis> spp.) |
| |
Authors: | K Vijayan S G Doss S P Chakraborti P D Ghosh |
| |
Institution: | (1) School of Agriculture, Food & Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia;(2) SARDI, GPO Box 397, Adelaide, SA, 5001, Australia |
| |
Abstract: | Late maturity α-amylase (LMA) is a genetic defect that is fairly widely spread in bread wheat (Triticum aestivum L.) germplasm, and recently detected in durum cultivars, which can result in unacceptably high α-amylase activity (low falling
number) in ripe grain. LMA has also been observed at unexpectedly high frequency and severity in synthetic hexaploid wheats
derived from the interspecific hybridisation of Triticum durum (AABB) and Aegilops tauschii (DD). Since synthetic hexaploids represent an important new source of resistances/tolerances to a range of biotic and abiotic
stresses for wheat breeders, there is a pressing need to understand the mechanisms involved in LMA in synthetics and develop
strategies for avoiding its adverse effects on grain quality. The objectives of this study were to firstly, compare the LMA
phenotype of synthetics that varied for plant height, secondly, to characterise the LMA phenotype in groups of synthetics
derived from the same durum parents and finally to determine whether LMA in primary synthetics is associated with the QTL
previously reported in conventional bread wheat. More than 250 synthetic hexaploids, a range of durum cultivars and a doubled
haploid population derived from Worrakatta (non-LMA) × AUS29663 (high LMA synthetic) were phenotyped and genotyped with markers
reported to be linked to LMA in conventional bread wheat and markers diagnostic for the semi-dwarfing gene, Rht1. More than 85% of synthetics were prone to LMA, approximately 60% ranked as very high. Genetic control of LMA in synthetic
hexaploids appeared to involve QTL located on 7B, and to a lesser extent 3B, similar to bread wheats. However, the LMA phenotype
of many synthetic hexaploids appeared to be more extreme than could be explained by comparisons with bread wheat even taking
into account the apparent absence of Rht1 in most genotypes. Other mechanisms, possibly triggered by the interaction between the AABB and DD genomes cannot be excluded.
The presence of wild type rht1 in most synthetic hexaploids and their extreme height is difficult to reconcile with the semi-dwarf, Rht1, stature of many of the durums used in the interspecific hybridisation process. Mechanisms that could explain this observation
remain unclear. |
| |
Keywords: | High α -amylase Semi-dwarfing gene (Rht1) Molecular markers |
本文献已被 SpringerLink 等数据库收录! |
|