籼稻耐低钾基因型的筛选

Screening indica Rice for K-efficient Genotypes

本研究针对我国钾矿资源短缺的基本国情 ,以业已建立的水培快速方法为筛选方法对 86种不同的基因型进行了筛选比较。结果表明无论是吸钾速率、钾素利用效率还是生物量 ,籼稻的基因型差异十分显著 :最大吸钾速率为IR4 5 138- 115 - 1- 1- 2 - 2 ,达 6 6 3.9,而最小吸钾速率为 IR4 776 1- 2 7- 1- 3- 6 ,仅只有 2 32 .6 nmol K+ plant- 1 h- 1 ,相差近 3倍 ;最大钾素利用效率为 76 0 1,达 88.9,而最小钾素利用效率为余赤 2 31- 8,仅 5 3.4 kg.kg- 1 ,前者比后者高 6 6 .0 ;至5叶期最大的生物量为 IR5 72 98- 31- 2 - 2 ,达 93.2 ,最小生物量为 Selection2 7- 1B,仅 2 0 .2 mg plant- 1 ,相差 4 .6倍。就 3个性状的基因型数目进行频数分布的分析表明 ,三者基本上呈正态分布 ,即最优秀的基因型和最差的基因型都居少数 ,绝大多数基因型的表现都是居中状态。说明无论是吸钾速率、钾素利用效率 ,还是生物量 ,优良基因型有着非常巨大的遗传潜力 ,利用生物多样性 ,开发基因潜能 。

China is much short of potassium resources according to today′s geological prospecting results and could only produce about 30 ton potash fertilizers per year. But it used about 650 ton of potash fertilizer in 2000. Hence, it has to import more than 95% of its consuming potash fertilizers. However, it is very rich in germplasm in crops. This very study was carried out to compare potassium influx rates, potassium utilization efficiencies and biomass of 86 indica rice genotypes from China National Rice Research Institute and IRRI by using the established quick method in hydroponics. The results revealed that the above three parameters of the tested genotypes were greatly different from each other. For instance, IR45138 115 1 1 2 2 was the fastest one and its influx rate was as much as 663.9 nmol K + plant -1 h -1 but IR47761 27 1 3 6 was the slowest, only 232.6 nmol K + plant -1 h -1 . The genotype, 7601 was the most efficient one in using potassium and it was able to produce 93.2 kg dry matter (DM) by using one kg potassium but the most K inefficient one, Yuchi 231 8 did only 53.4 kg kg -1 . Biomass of IR57298 31 2 2 was the biggest, as much as 93.2 mg DM per plant but the smallest one, Selection27 1B synthesize 20.2 mg DM per plant. All the above results imply that there is a great potential to alleviate the status of K shortage by developing K efficient gemplasm in rice breeding. New rice cultivars, tolerant to low K stress, bred from the K efficient genotypes as the genetic parents are able to supersede potassium mineral resources partially. Genetic and physiological research on tolerance of rice to low available K level in farmland is very important to our sustainable strategy in economy development.