不同年代育成的中籼水稻品种干物质累积和钾素吸收及分配

旨在研究我国不同年代中籼水稻品种干物质的积累以及钾素吸收和分配规律,以期为水稻钾素高效利用及优良品种选育提供理论依据。采用田间试验,选取1940-2000年以来各时期生产上大面积推广的中熟籼稻品种共9个,随机区组设计,3次重复。各中稻品种随着品种应用年代的演进叶面积指数以及生物产量获得大幅度提升。现代水稻品种在穗分化期后其生长速率显著增加,干物质积累速率也显著高于早期品种。齐穗期后各品种的干物质累积量与籽粒产量大致相当,且现代水稻品种干质量累积量显著高于早期品种,子粒产量显著增加。不同年代中籼水稻品种的钾素累积量随着品种演进显著增加。不同年代中籼水稻品种的钾素累积量随着品种演进显著增加。水稻对钾的吸收主要在齐穗期之前完成,抽穗到成熟期钾的吸收量减少。籽粒中的钾大部分来自于营养体的再转移,茎中钾含量尽管最多,但转移量较少,主要来源于叶片的转移。2000年以后的品种如两优培九和扬两优6号叶片中钾素的转运最多。随着水稻品种更替,植株干物质以及钾素的累积量逐步增加;在成熟期从营养体向籽粒中转移钾的量显著提高。水稻籽粒中的钾主要来源于叶片的转运,与早期水稻品种相比,现代水稻品种叶片钾素转移量最大。

Accumulation and Distribution of Dry Matter and Potassium in Mid-season Indica Rice Cultivars Applied at Different Decades

The experiment was conducted to investigate the differences in dry matter accumulation,as well as potassium (K) uptake and distribution in mid-season indica rice cultivars applied at different decades in China.In this study,9 typical mid-season indica rice cultivars applied in the production in the Middle-lower Yangtze Area during the last 60 years were used under field conditions with randomized block design and three replications.Leaf area index and biomass were progressively increased with the improvement of cultivars.The growth rate of modern rice varieties significantly increased and dry matter accumulation increased higher than those in the early varieties after panicle initiation.The dry matter accumulation of all varieties were roughly the same as the gains of whole plant after heading period,and the dry matter accumulation of modern varieties was significantly higher than that of the early varieties.K contents were progressively increased with the improvement of cultivars.Most of K in all rice varieties was taken up before panicle initiation and there was decreased in the uptake of K from heading to maturity.Most of the potassium in grain comes from the retransfer of the vegetative body,mainly from the transfer of the leaves.There was more K retranslocated from the leaves of the modern varieties Liangyoupeijiu and Yangliangyou 6 compared with the old varieties.Dry matter and K accumulation were progressively increased during the evolution for mid-season indica rice cultivars.Compared with old cultivars,the K translocation into grain of modern cultivars in maturation period was improved.K in grain was mainly translocated from leaves,and K translocation in leaves were progressively increased with the improvement of cultivars.