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

人们担心，在未来全球变暖的情况下，水资源的短缺将变得比目前更严重，植物从土壤中吸收水分成为调节世界许多地区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际PA到坚硬土层(Root PA)，使作物能够吸收存在于深层土壤中的未使用的水分。本研究对小麦根际PA的遗传变异及其遗传方式进行了研究，获得了以下结果：1.小麦根际PA的遗传变异及其遗传方式。研制了一种适用于小麦根部PA测定的石蜡-凡士林混合层(PV-POT)罐。结果表明，硬土层土壤根际PA的遗传差异与PV-Pot2检验结果吻合较好。用PV盆栽技术对ICARDA和CIMMYT选育的现代高产硬粒小麦品种的根PA进行了评估，结果表明，与在硬土层上生长良好的埃塞俄比亚陆地小种相比，硬粒小麦品种的根PA较差。此外，国内面包小麦品种的根际亲和力存在较大差异，表明优良品种可作为改良根际亲和力的遗传资源。比较了矮秆硬粒小麦等基因系控制株长和收获指数的根PA。矮秆与根PA间未发现显著关系，表明二者在遗传上独立。此外，与根PA相关的QTL位于6A染色体的头臂最下部，定位于硬粒小麦MAP群。

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.