水稻品种化感潜力的双重评价与筛选

以初筛获得的7份水稻品种为材料,用特征次生物质标记法在HPLC上测定化感指数AI值并结合田间小区试验进行双重评价与筛选,得到3份既具高化感指数又具较高田间抗草活性的水稻化感品种(系),它们是:我国台湾品种I-Kung-Pao、Parahainakoru和大陆品种HB-1。它们对无芒稗根长抑制率分别达57%、64%、55%,均超过50%;其化感指数分别是0.61、0.56、0.59,均与美国化感潜力品种PI312777的化感指数0.59相近;结果表明,水稻品种I-Kung-Pao、Parahainakoru和HB-1是我国宝贵的化感品种资源。

Evaluation of allelopathic potential in rice germplasm

Weeds in paddy are known to reduce rice yield severely. Use of herbicides for weed control has given rise to many problems related to environmental protection, herbicide-tolerant weeds and contamination of agricultural products, which endangered the sustainable development of agriculture. Since last decades, ecological methods for weed control have been developed. Research on rice allelopathy against weeds that started in late 1980's had been encouraging and developed fast. It is one of the first steps for research on rice allelopathy against weeds that involved the screening potential of rice germplasm (Oryza sativa L.). The objective of this research was to determine the allelopathic rice germplasm with both high allelopathic index (AI) and high activity against weeds. Seven rice germplasm (Oryza satica L.) were used as the test materials in this experiment which were primarily screened by bioassay methodology. The allelopathic indices (AIs) were determined with HPLC by the special secondary metabolite marking method, and then, the field experiments were conducted to confirm the weed control effects derived from rice varieties. High allelopathic activity against barnyardgrass (Echinochloa crusgalli L.) of the three rice germplasm (I-Kung-Pao, Parahainakoru from native Taiwan and HB-1 from Mainland China) was detected among the tested rice germplasm. The inhibitory ratios of barnyardgrass root length were 57, 64 and 55%, respectively. The AIs were 0.61, 0.56 and 0.59, respectively, similar to the allelopathic rice PI312777 from the United States considered as control in the experiment. Satisfactory weed control effects in field were obtained as reductions of both the plant density and the fresh weight of barnyardgrass. On short, the rice varieties of I-Kung-Pao, Parahainakoru and HB-1 were regarded as valuable rice germplasm with high allelopathic potential in China.