两系杂交稻对磷素营养吸需特性研究

Studies on Two-line System Hybrid Rice's Character of Absorbing Phosphate Nutrition

二系法杂交稻是在三系杂交稻的基础上发展而成的，目前一 批比现有三系杂交稻增产 １５％ 以上的两系杂交组合已开始进入大面积推广应用阶段，其基础研究也取得了很大的进展。本文应用放射性３２ Ｐ示踪法标记不同的杂交组合，以了解两系杂交稻对磷素营养的吸收运转特性，以便充分发挥两系杂交稻的高产优势，为科学合理施肥提供依据。结果表明①不同的杂交组合对磷素营养的吸收量以两系杂交组合＞ 三系杂交组合＞ 常规组合，早稻分别比三系组合和常规组合高 ９７％ 和 ２０１８％ ，晚稻分别高 １８５３％ 和 ３８６５％ ，在苗期浸根亦表现出同一趋势。②水稻所吸收的磷素 ８０％ 由土壤供从给，只有 ２０％ 由肥料供给 。二系杂交组合吸收土壤的磷高于三系组合和常规组合，而吸收肥料磷的比率要低于常规组合和三系组合，但吸收磷的总量以二系杂交组合为最高。③水稻吸收的磷大部分积累在植株生长较旺盛的部位，在分蘖期和孕穗期磷在水稻茎秆中含量较多，到成熟期则大部分磷都运转到谷粒中累积，约占吸收总量的 ５０—７０％ 。④磷在植株单位干物中的含量，在分蘖期以二系杂交组合高于三系组合和常规品种，早稻分别高 ３１１３—３７６２％ ，晚稻高１７５８—２８９２％ 。

Two-line systen hybrid rice is developeol on the basis of Three-line systen hybrid rice,presently,many Two-line systen hybrid rice strains which of yields increase 15 percent more than Three-line system hybrid rice are being into the period of great releasement. and its basic reasearch has made great development, In order to bring into full play the charaeter of Two-line systen hybrid rice's high yield and provide scientific basis for reasonable fertilizer application, We applied differend hybrid rice strains marked by radioactive tracer 32 P to understand the character of Two-line system hybrid rice's absorbing and transporting phosphate nutrition. Resucts proved that:①the absorbed phosphate content of different hybrid rice is Two-line system hybrid rice>Three-line system hybrid rice>Conventional rice,amony which early rice increases 9.7 percent more than Three-line system hybrid rice, 20 18 percent more than Conventional rice and late rice increases by 18.53 percent and 38.65 percent.The immersing root treatment in seedling stage shows a similar tread; ② 80 percent of rice's absorbing phosphate is provided by soil,and only 20 percent is provided by fertilizer. for the phosphate absorbed in soils, Two-line system hybrid rice is more than Three-line system hybrid rice and conventional rice,and for the phosphate absorbed in fertilizer,Two-line system hybrid rice is lower than Three-line system hybrid rice and Conventional rice, but the total phosphate is highest in Two-line system hybrid rice; ③The majority of rice's absorbing phosphate is accumulated in rapidly-growing position of plant.In the tillering stage and boating stage,phosphate is more in rice's stem.In maturity stage,the majority of phosphate is transported to the grains,grain's phophate is about 50～70 percent of the total absorbed phosphate;④For the phosphate content of plant dry matter in tillering stage ,Tivo--Line system hybrid rice is more than Three-line system hybrid rice and Conventional rice ,among which early rice is more about 31.13-37.62 percent and Late rice is more about 17.58-28.92 percent.In booting stage and maturity,the phosphate content of plant dry matter is highest in Conventional rice.