Analysis of genetic variation in wheat for root penetration ability to hard soil layer

恐怕在未来全球变暖的情况下，缺水问题将比现在更加严重，植物从土壤中吸收水分将成为世界上许多地区调节作物生产力的主要因素。为了维持与世界人口增长相适应的粮食生产，我们需要通过改善根系PA到硬土层（根系PA），使作物能够吸收深层土壤中未利用的水分。本研究对小麦根系PA的遗传变异及其遗传类型进行了研究，得到了以下结果：1。研制了一种适用于小麦根系PA测定的石蜡-凡士林混合层盆栽（PV盆栽）。结果表明，硬土层土壤根系PA的基因型差异与PV盆栽试验结果吻合较好。在ICARDA和CIMMYT选育的现代硬粒小麦高产品种中，用PV盆栽评价的根系PA低于在坚硬土层中生长良好的埃塞俄比亚陆地品种。此外，国产面包小麦基因型的根系PA存在较大的变异，表明可以利用优势基因型作为改善根系PA的遗传资源。比较了矮秆硬粒小麦等基因系控制株长和收获指数的根系PA。矮秆性状与根系PA之间的关系不显著，说明两个性状在遗传上是独立的。此外，在硬粒小麦图谱组中，确定了与根PA相关的QTL位于染色体6A的头臂末端底部。

It is afraid that under future global warming the shortage of water becomes more serious beyond the present and the plant water absorption from the soil becomes the main factor which regulates the productivity of the crop in many areas of the world. To maintain food production corresponding to the population growth of the world, we need to make available for the crops to absorb the unused water existing in deep soil by improving root PA to hard soil layers (root PA). The present research examined the genetic variation and its heredity style about root PA of wheat, and the following results were obtained.1. A pot with a paraffin-Vaseline mixed layer (PV pot), which was suitable for the measurement of root PA in wheat, was developed. It was verified that a genotypic difference in root PA in fields with hard soil layer agreed well with those evaluated by the test with PV pot.2. Root PA evaluated with PV pot in modern high yielding cultivars of the durum wheat bred by ICARDA and CIMMYT was inferior to that of Ethiopian land races which grew well in fields with hard soil layers. Moreover, a big variation existed in the root PA tested for the domestic bread wheat genotypes, suggesting that superior genotypes could be used as the heredity resources to improve root PA.3. Root PA of isogenic lines of durum wheat about dwarf which controls plant length and harvest index was compared. Significant relations between dwarf and root PA weren' t recognized, indicating that the two characters were hereditarily independent. Furthermore, QTL related to root PA was located in the head arm extreme bottom part of the chromosome 6A was defined in the map group of durum wheat.