不同覆土深度对水稻出苗的影响

Effects of Different Planting Depths on Rice Seedling Emergence

摘要:

本文研究覆土深度对不同水稻品种出苗率的影响,以期为水稻直播品种选择提供理论基础。研究结果表明,供试水稻品种出苗率随着播种深度的增加而下降,中胚轴伸长长度显著不同,并且覆土深度对各品种中胚轴伸长长度有不同的影响。辽粳399和辽粳401中胚轴伸长长度最长,分别为1.65～4.35 mm和2.53～4.54 mm,并且覆土深度越深,中胚轴伸长长度越长。盐粳48、辽粳212、铁粳14、辽优9906等品种中胚轴伸长长度不受覆土深度的影响,但胚芽鞘长度随着覆土深度的增加显著增加,说明这些品种出土动力主要来自胚芽鞘的伸长。本研究中,辽粳212、盐粳48、辽粳401等5个品种在覆土深度为2 cm时出苗率超过70%。因此,从出苗率角度来说,可作为直播的品种选择。

Abstract:

The effects of different planting depths on the seedling emergence rate of different rice varieties were studied to provide a theoretical basis for direct seeding varieties of rice cultivation. The results showed that the seedling emergence rate of the tested rice varieties decreased with the increase of planting depth. The mesocotyl elongation length was significantly different, and the planting depth had different effects on the elongation length of the mesocotyl of different varieties. Liaojing 399 and Liaojing 401 had the longest mesocotyl elongation length, ranging from1.65～4.35 mm and 2.53～4.54 mm, respectively. The deeper the planting depth was, the greater the mesocotyl elongation length was. In Yanjing 48, Liaojing 212, Tiejing 14 and Liaoyou 9906, the elongation of the mesocotyl was not affected by the planting depth, but the coleoptile length increased significantly with planting depth. The above indicated that the coleoptile elongation might play a key role in the seedling emergence. In this study, the seedling emergence rate of five varieties including Liaojing 212, Yanjing 48, Liaojing 401 was over 70% when the planting depth was 2 cm. Therefore, from the perspective of the seedling emergence rate, it can be used as a variety selection for direct seeding.