干旱胁迫下保水剂及与椰糠交互作用对“上海青”小白菜生理特性的影响

Effects of SAP and SAP Mixted Coir Pith on Physiological Characteristics of Brassica rapaL.‘Shanghaiqing' Under Drought Stress

以聚丙烯酰胺型保水剂为试材，以“上海青”小白菜为研究对象，采用不同剂量的保水剂及保水剂＋椰糠混合处理“上海青”幼苗，研究比较了干旱胁迫下不同剂量保水剂与椰糠交互作用对“上海青”小白菜生理特性的影响，以期为海南季节性干旱期在砖红壤上进行蔬菜栽培合理使用保水剂提供参考依据。结果表明：施用保水剂及保水剂＋椰糠后各处理均优于CK，其中叶绿素和根系活力随干旱的加强而下降，其下降幅度为CK〉B1（15kg／hrn2保水剂）〉133（75kg／hm2保水剂〉YBl（15kg／hm2保水剂＋15kg／hm2椰糠）〉]32（45kg／hm2保水剂）〉YB2（45kg／hm2保水剂＋45kg／hm2椰糠）〉Ym（75kg／hm2保水剂＋75kg／hm2椰糠）；游离脯氨酸含量和丙二醛含量随干旱的加强而增加，上升幅度分别为CK〉B1〉YB1〉133〉132〉Y]32〉YB3和CK〉B1〉B3〉YB1〉B2〉YB2〉YB3；B1～YB3的生存时间较CK延长0．33、2．67、1.33、0．67、3．33、5．00d。所以在海南砖红壤上栽培“上海青”时单施保水剂选／32（45kg／hm。）抗旱性最佳；如果与椰糠混施，选择YB3（75kg／hm2保水剂＋75kg／hm2椰糠）较为适合。

Taking polyacrylamide type water retention agent as material,Brassica rapa L. ＇Shanghaiqing＇ as study object, different doses of SAP polycrylamide and SPA polycrylamide mixted coir pith were applied to seedling of Brassica rapa L. ＇Shanghaiqing＇ to study its physiological characteristics under drought stress, in order to provide references for SAP that used rationally on vegetable cultivation in Hainan＇ brick-red soil during seasonal drought. The results showed that the treatments of SAP and SAP mixted coir pith were better than CK, which chlorophyll content and root activity decreased with the strengthening of drought, the order was CK〉B1 （15 kg/hm2 SAP） 〉B3 （75 kg/hm2 SAP） 〉YB1 （15 kg/hm2 SAPq-15 kg/hm2 coir pith）〉B2（45 kg/hm2 SAP）〉YB2（45 kg/hm2 SAP＋45 kg/hm2 coir pith）~YB3 （75 kg/hm2 SAP＋ 75 kg/hm2 coir pith）, and the content of proline and MDA increased with the strengthening of drought,the order was CK〉B1〉YB1〉B3〉B2〉YB2〉YB3 and CK〉B1〉B3〉YB1〉B2〉YB2〉YB3 respectively, and B1-YB3 survival time were extended by 0. 33,2. 67,1.33,0. 67,3. 33,5.00 days. So B2 （45 kg/hm2 ） that single application of SAP was best to resist the drought for ＇Shanghaiqing＇ and was cultivated in brick-red soil of Hainan,and YB3 （75 kg/hm2 SAP＋75 kg/hm2 coir pith） was more suitable if SAP rnixted coir pith.