Evaluation of CIMMYT conventional and synthetic spring wheat germplasm in rainfed sub-tropical environments. I. Grain yield

Hexaploid spring wheat (Triticum aestivum L.) germplasm from CIMMYT's breeding program in Mexico has assisted wheat improvement in Australia, particularly in the north-eastern region where terminal drought frequently reduces grain yield. A total of 273 conventional hexaploid and derived synthetic hexaploid spring wheats from CIMMYT, along with 15 locally adapted Australian cultivars (Oz lines), were evaluated for grain yield over four years in a total of 27 environments in Australia's north-eastern wheat region. The CIMMYT conventional spring wheats were from a Seri/Babax recombinant inbred line population (SB lines), elite entries from an International Adaptation Trial (IAT lines) introduced to Australia between 1999 and 2004 and from CIMMYT screening nurseries introduced to Australia in 2004–2005 (SW lines). Synthetic wheats (SYN lines) were also from these nurseries as well as from a separate program of synthetic wheat introductions to Australia over 2001–2004.     

小麦低分子量谷蛋白(Glu-3)亚基及高分子量醇溶蛋白(Gli-1)的分离图谱辨读方法

小麦胚乳贮藏蛋白质中低分子量谷蛋白亚基和高分子量醇溶蛋白组成和含量对品质也有重要作用。二者的编码基因紧密连锁，分子量和电泳中的迁移率接近，为其分离和标定增加了难度。用20个小麦标准品种为对照，结合Gupta汇总的Gli-3位点等位基因变异图和Jackson汇总的Gli-1位点等位基因变异图，可对分步法SDS-PAGE分离图谱中低分子量谷蛋白亚基组成（Glu-3）和A-PAGE图谱中高分子量醇溶蛋白组成（Gli-1）进行辨读，获得任何一个小麦品种Glu-3和Gli-1基因组成。     

显性雄性不育硬粒小麦（Triticum durum）和二粒小麦（Triticum dicoccum）选育

用已育成的显性雄性不育六倍体小黑麦为母本分别与硬粒小麦、二粒小麦及黑麦杂交,并每代选不育株用原父本回交。结果表明,来源于太谷核不育小麦4D染色体上的Ms2（Tal）基因已易位到A或B染色体组的某一条染色体上。从而育成了显性核不育硬粒小麦和二粒小麦。     

Evaluation of CIMMYT conventional and synthetic spring wheat germplasm in rainfed sub-tropical environments. II. Grain yield components and physiological traits

CIMMYT hexaploid spring wheat (Triticum aestivum L.) germplasm has played a global role in assisting wheat improvement. This study evaluated four classes of CIMMYT germplasm (encompassing a total of 273 lines), along with 15 Australian cultivars (Oz lines) for grain yield, yield components and physiological traits in up to 27 environments in Australia's north-eastern region, where terminal drought frequently reduces grain yield and grain size.Broadly-adapted CIMMYT germplasm selected for grain yield had greater yield potential and improved performance under drought stress, being up to 5% greater yielding in High-yielding (mean yield 429 g m⁻²) and 4-10% greater yielding than adapted Oz lines in Low-yielding environments (mean yield 185 g m⁻²). Whilst maintaining statistically similar harvest index and spikes m⁻² compared to broadly-adapted Oz lines across all environments, sets of selected CIMMYT lines had greater canopy temperature depression (0.18-0.27 °C), dry weight stem⁻¹ (0.20-0.37 g), increased grains spike⁻¹ (0.8-3.4 grains), grain number m⁻² (ca. 20-800 grains), and maturity biomass (56-83 g m⁻²). Compared to selected Oz lines, broadly-adapted CIMMYT lines had a smaller reduction in Low compared to High-yielding environments for these traits, especially dry weight stem⁻¹, such that CIMMYT lines had ca. 25% and 10% greater dry weight stem⁻¹ than the Oz lines in Low- and High-yielding environment groups, respectively. Broadly-adapted CIMMYT germplasm also had slightly higher stem water soluble carbohydrate concentration at anthesis (ca. 6 mg g⁻¹), which contributed to their higher grain weight (ca. 0.5 mg grain⁻¹), and maintained an agronomically appropriate time to anthesis and plant height. Thus current CIMMYT germplasm should be useful donor sources of traits to enrich breeding programs targeting variable production environments where there is a high probability of water deficit during grain filling. However, as multiple traits were important, efficient introgression of these traits in breeding programs will be complex.