通过胚胎拯救将野生稻耐旱特性转移到栽培稻进行远缘杂交初探

众所周知，农业用水的缺乏严重影响着世界干旱地区农业的发展，尤其影响着水稻的生产。育出具有耐旱特性的水稻品种从而经济地利用水分是一个重要的课题。前人的研究表明野生稻Oryza属中有许多种具有耐旱性，如果水稻栽培种也具有耐旱性，那将会更能适应环境节约用水，大大地提高水稻的收获面积及适应性。Oryza meridionalis 和Oryza australiensis具有耐旱特性，试验旨在通过远缘杂交将野生稻Oryza meridionalis 和 Oryza australiensis的耐旱特性转移到栽培稻Oryza Sativa。用Oryza meridionalis花粉对Oryza sativa共2419朵小花进行杂交授粉，并对杂交获得的18粒F1代未成熟种子进行了胚胎拯救，最终仅有一粒F1种子发芽并发育成植株，并获得一粒F2代种子，其杂交率为0.46%，萌芽率为50%，F1代杂种的结实率为0.024%；用Oryza australiensis花粉对Oryza sativa共1848朵小花进行杂交授粉，并对杂交获得的48粒F1代未成熟种子进行了胚胎拯救，有11粒F1种子发芽并发育成植株，全部不育，其杂交率为0.60%，萌芽率为31.1%。同时，还对F1代杂种的形态学和农艺学特性进行了观察，最后还讨论了提高杂交率的方法及伪杂种的问题。

Preliminary Report on Transfer the Character of Drought Tolerance from Wild Rice (Oryza meridionalis and Oryza australiensis) to Cultivated Rice (Oryza sativa) via Distant Hybridization and Embryo Rescue

It is well known that the lack of water in some areas of the world is threatening their agriculture, especially influences the growing and productivity of rice. So it is very important to breed new rice variety, which has drought tolerance, character or uses water economically. For example, in Beijing of China, rice harvesting area was very large in the past. Because of the lack of water, the available water is not enough for people to drink and not even more for rice planting. Consequently the area of rice planting in Beijing is decreasing every year. Up to now the area of rice planting is not over 1,000 hectares. There are diversified pattern of drought tolerance in Oryza spp. If Oryza has drought tolerance trait, the cultivars would be environmental sound and economical viable. There would be great potential to increase the rice harvesting area and adaptability. The possible donors of character for drought tolerance are Oryza meridionalis and Oryza australiensis. In this experiment drought tolerance was transferred from wild rice species Oryza meridionalis and Oryza australiensis to cultivated rice Oryza Sativa through distant hybridization. The 2,419 florets of Oryza sativa were pollinated with Oryza meridionalis and 18 immature seeds of the F1 hybrid obtained were cultured for embryo rescue. Only one seed could germinate to be F1 hybrid plant. The plant set one F2 seed. The rate of crossability ranged from 0 to 0.46%, the rate of germination ranged from 0 to 50% and the rate of seed set of the F1 hybrid plant was 0.024%(1/4,211). The 1,848 florets of Oryza sativa were pollinated with Oryza australiensis and 48 immature seeds were obtained were cultured for embryo rescue. 11 of the 45 seeds could germinate to be F1 hybrid plants. They were all male sterile, the rate of crossability was 0.60% and the rate of germination was 31.1%. Morphological and Agronomic characters of the F1 hybrids of both crosses were observed. Finally advisable days after pollination for embryo rescue and "false" hybrid problem were discussed.