籼型杂交稻耐低钾基因型的筛选

Screening Hybrid Combinations of Indica Rice for K-efficient Genotypes

针对我国钾矿资源短缺、但作物种质资源非常丰富的基本国情 ,从作物遗传多样性的角度 ,以稻株的吸钾速率、钾素利用效率和生物量等为评价指标 ,用业已建立的水培快速筛选方法对 2 8种不同组合的籼型杂交稻进行了比较。结果表明 ,无论是吸钾速率、钾素利用效率还是生物量 ,不同组合的差异十分显著。威优 6 4的吸钾速率最大 ,达 6 84.9nmolK+ ·plant-1·h-1,而协A/ 90 9的吸钾速率最小 ,仅 45 7.2nmolK+ ·plant-1·h-1,相差 49.8%;五叶期汕A/ 90 9钾素利用效率最高 ,达 81.8kg/kg,而汕优 6 4钾素利用效率最低 ,仅 5 5 .9kg/kg ,相差46 .3%;汕A/46 6 3 5的生物量最大 ,达 10 0 .8mg/ plant,协A/ 46 6 3 4生物量最小 ,仅 5 9.1mg/ plant,相差 70 .6 %。

According to today's geological prospecting results China is much short of potassium resources and can only produce about 30 t potash fertilizers per year. But it used about 650 t of potash fertilizers recently. Hence, it has to import more than 95% of the potash fertilizers for consuming. However, it is very rich in germplasm in crops. This research was based on biodiversity of rice and 28 genotypes from China National Rice Research Institute and IRRI were screened by using the established quick method in hydroponics. The results showed that all genotype in different combination differed significantly in absorption rates of potassium, in potassium utilization efficiencies and biomass per plant at five-leaf stage. Weiyou64 was the fastest one and its absorption rate was as much as 684.9 nmol K +·plant -1·h -1, but XieA/909 was the slowest, the rate was only 457.2 nmol K +·plant -1·h -1. ShanA/909 was the highest one in potassium using efficiencies and it was able to produce 81.8 kg dry matter (DM) by using one kg potassium. Shanyou64 did only 55.9 kg/kg. Biomass of ShanA/4663-5 was the biggest, as much as 100.8 mg DM /plant, XieA/4663-4 synthesized 59.1 mg DM/plant. All the above results indicated that K-efficient rice genotypes were very potential to save potassium. Breeding new rice cultivars which are tolerant to low-K stress from the K-efficient genotypes as the genetic parents is 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.