锰施用量对香稻生理特性和糙米锰含量的影响

【目的】探究硫酸锰(MnSO_4)不同施用量对香稻生理特性和糙米中锰(Mn)元素含量的影响,为香稻的优质栽培提供理论依据。【方法】以常规香稻美香占和农香18为材料,通过盆栽试验,采用随机区组排列,设置4个基施MnSO_4处理,即分别施入MnSO_46.67(Mn1)、10.00(Mn2)、13.33(Mn3)、16.67(Mn4)mg·kg~(-1),以不施入MnSO_4作为对照(CK)。【结果】与CK相比,Mn4处理更有利于提高香稻糙米中Mn含量,美香占早、晚造增幅分别为22.02%和6.75%;农香18早、晚造增幅分别为1.48%和4.26%。基施MnSO_4能较好地增加早、晚造香稻孕穗期及后期的茎秆和叶片中全Mn含量,2个品种均以Mn4处理的结果较好。基施MnSO_4,以Mn4处理最有利于早、晚造香稻不同生育期叶片净光合速率(Pn)的提高和植株干物质积累量的增加;Mn4处理更有利于增强早、晚造各生育期叶片超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,降低叶片丙二醛(MDA)含量。【结论】适量基施MnSO_4有利于提高香稻的Pn,增强香稻对外界环境的抗逆性和适应性,促进香稻的生长,提高香稻茎叶中全Mn含量,最终促进糙米中锰元素的积累;本研究最佳施用量为基施MnSO_416.67 mg·kg~(-1)。

Effects of Mn application amounts on physiological characteristics and Mn content of aromatic rice

Objective] To investigate the effects of MnSO 4 basal applications on physiological characters and Mn content of aromatic rice , and to provide a theoretical basis for cultivating high-quality aromatic rice .Method] Pot experiment was carried out using Meixiangzhan and Nongxiang 18 as planting materi-als.Four basal applications of MnSO4 were employed with the concentrations of 6.67 (Mn1), 10.00 (Mn2), 13.33 (Mn3) and 16.67 (Mn4) mg? kg -1 respectively.There was a control treatment (CK) with none MnSO 4 application .The experiment was arranged in a randomized block design .The Mn con-tents of leaves , stems and brown rice grains were measured .The enzyme activities of superoxide dis-mutase (SOD) and peroxidase (POD), and the content of malondialdehyde (MDA) in rice leaf were investigated .Result] Compared to the control , Mn4 was more beneficial to increase the Mn content of brown rice grains in early and late seasons by 22.02% and 6.75% respectively for Meixiangzhan , and 1.48% and 4.26%respectively for Nongxiang 18 .Mn4 treatment was better to increase the Mn content in the stems and leaves of early and late aromatic rice varieties after booting stages .Mn4 treatment im-proved the net photosynthetic rate of leaf and dry mass of above-ground of early and late aromatic rice va-rieties.Moreover, Mn4 treatment was more effective to improve the SOD and POD activities and decrease the MDA content in the leaves of early and late aromatic rice varieties .Conclusion] Appropriate basal application of MnSO 4 would be more effective to improve the net photosynthetic rate and the Mn contents of stem, leaf and brown rice grains , enhance the resistance , adaptability and growth of aromatic rice vari-ety.The optimal application amount of MnSO 4 is 16.67 mg? kg -1 in this study .