湘中、湘东地区早籼稻耐土壤潜育性评价

APPRAISAL OF EARLY RICE TOLERANCE TO GLEYIC PADDYSOIL IN CENTRAL AND EASTERN HUNAN

我国南方稻区的主要低产稻田是潜育性稻田,约有一亿亩。挖掘其“潜在生产力”,种植耐潜育性土壤逆境胁迫能力较强的水稻品种,则是简便、经济而有效的重要途径之一。本文就几个早籼稻品种(组合)对潜育性稻田的生态适应性进行了较系统的观测,并初步提出了耐潜育性的几个鉴定指标,诸如根系生长量和幼穗分化期根系氧化力;分蘖早期茎蘖增长速率;分蘖后期单株干物质产量;乳熟期剑叶片过氧化氢酶活性GDI和光合强度等。上述鉴定指标,综合应用于水稻品种生态适应性和耐潜育性育种研究,有助于提高水稻抗逆性育种的效率。

The gleyic paddysoil, characterized by excess Fe^(++) Mn^(++), S^(--) low Eh, low temperature of water and soil, and excess organic acids, is the most important adverse soil type in eastern and central Hunan, Five early indica rice varieties (lines, including one hybrid rice) were used in the field (gleyic paddysoil) evaluation from 1987 to 1989 Changsha, Hunan, aiming at evaluating the differences in eco-adaptability to the adverse soil and screening out some tolerant varieties. lines and hybrid rice. We have put forward a comprehensive system for evaluating the tolerance of rice to the stress soil condition and established the evaluating method with aseries of progressive Fe^(++) added solution.The results show that root mass and root oxidizing activity at booting stage, tillering rate at early tillering stage, dry matter production at late tillering stager, catalase GDI and photosynthesis rate of flag leaf at milk stage, are useful appraisal indexes to evaluate the tolerance of rice to gleyic paddysoil. Using these appraisal indexes we found the hybrid combination 'Weiyou 49' shows the best tolerance, while new lines, 'Changtaofu No, 2' and 'Changtaofu No. 1', show intemediate, but the local widely-cultivated varieties, 'Zhefu 802' and 'Xiangzhaoxian No. 4', show the weakest tolerance to the gleyic paddysoil, Main differences exist at rootsystem characters and agronomic characters. In conclusion. these appraisal indexes can be used in study of rice ecoadaptability to gleyic paddysoil and the breeding of gleyic paddysoil tolerance of early indica rice in order to raise the efficiency of selection.