水分矿化度对不同品种水稻发芽率的影响

Effects of Water Mineralization on Germination Rate of Two Rice Varieties

淡水资源亏缺是限制盐渍化土壤作物出苗和生长的关键因素之一,为探寻盐渍化农田水稻出苗与水分矿化度的关系,选取非耐盐品种圣稻735和耐盐品种盐粳456为试材,通过温室盆栽试验和室内培养箱模拟试验开展不同矿化度灌溉水对水稻不同时间发芽率及土壤盐分、pH值的影响。结果表明,水稻发芽率随水分矿化度增加而降低,发芽时间推迟,矿化度越高,推迟时间越长,至16 d时发芽率达到最高。水稻发芽率与灌溉水矿化度呈显著负相关,相同水分矿化度时,圣稻735发芽率高于盐粳456,且发芽日期早于盐粳456,圣稻735发芽盐害程度弱于盐粳456。以中度矿化度水灌溉时,两品种水稻发芽率均低于50%,其受盐害程度较重。本研究表明,灌溉水矿化度增加显著提高土壤盐分,进而导致水稻发芽受抑制,在弱矿化水灌溉条件下,圣稻735发芽状况优于盐粳456,而弱矿化水可用于灌溉淡水资源受限的盐渍化农田水稻发芽,以保证一定程度的出苗率。

Limited fresh water plays a critical role on crops germination and growth in salinity lands. In order to research the relationship between rice germination and water mineralization, the effects of irrigation water with different salinity on rice germination rate at different time, soil salinity and pH value were studied by a pot experiment in greenhouse and a culture experiment in constant-temperature incubator with two rice varieties, Shengdao 735 （salt-sensitive） and Yanjing 456 （salt-tolerance）. The results showed that the germination rate of rice decreased with the increase of water salinity, and the germination time was delayed. The higher the salinity was, the longer the delayed time was. The germination rate reached the highest on the 16th day. The germination rate of rice was negatively correlated with the salinity of irrigation water. At the same water salinity, the germination rate of Shengdao 735 was higher than that of Yanjing 456, and the germination date was earlier than that of Yanjing 456, so the degree of salt damage to Shengdao 735 was weaker than that to Yanjing 456. When the water was with moderate salinity, the germination rate of the two varieties were both lower than 50%, and the degree of salt damage was heavier. The results showed that the increase of salinity of irrigation water significantly increased soil salinity, which led to the restraint of rice germination. Under the condition of weak mineralized water irrigation, the germination status of Shengdao 735 was better than that of Yanjing 456. Weak mineralized water could be used to germinate rice in saline farmland with limited freshwater resources to ensure a certain degree of germination rate.