Study On An Interspecific Hybrid Between Oryza Sativa L. And Oryza Meyeriana And The Sterility Of The F₁ Hybrid

Rice (Oryza sativa) is one of the most important crops in China. It also plays an important role in the world. Now most rice varieties in China are with very narrow genetic bases.The limited genetic diversity of rice renders it more vulnerable to disease and insect epidemics and jeopardizes the potential for sustained genetic improvement over the long term. Bacterial blight of rice caused by Xanthomonas oryzae pv.oryzae is one of the most destructive diseases in China. It is less effective to defend it with chemical bactericide. Developing resistance cultivars is generally considered to be the most economical and effective means of disease control. Since resistant resources in rice varieties are very few, it is very necessary to search new resistance resources. Oryza meyeriana is one of the three wild species in China, and it has a lot of valuable genes such as bacterial blight resistance, blast resistance, brown planthopper resistance, yellow stembores resistance, drought tolerance, shade tolerance and so on. O. meyeriana is a distant related wild species of rice and contains the GG genome, and it is very difficult to initiate sexual hybridization between it and Oryza sativa L. In order to introgress the valuable genes from O. meyeriana into cultivated rice and take advantage of them, a lot of methods were tried to get the BC₁F₁. At last the sterile mechanism of F₁ hybrid was studied. The main results are as follows:1 The genetic diversity analysis between O. meyeriana and one variety (IR24) of Oryza sativa L. was carried out by 159 SSR primer pairs allocating on 12 chromosomes of rice respectively. From the results we can see that the polymorphisms are very high between them and the amplification products of some primers are fainter in O. meyeriana. It implied that the genetic diversity between them is very high.2 In order to reduce the extremely low crossability of O. meyeriana with...