绿比多对匍匐剪股颖耐热性的影响

Effects of LBD on improving heat tolerance in creeping bentgrass

绿比多是以氨基酸和多肽为主要成分的一种新型生物刺激素,具有提高植物耐热性的作用,但其提高植物耐热性的生理机制尚不清楚。本研究以匍匐剪股颖(Agrostis stolonifera)为试材,生物刺激素绿比多为试验药剂,浦绿(Primo MAXX)和叶面肥为对照药剂,设置绿比多高温处理前喷施1次(L-preH-1)、绿比多高温处理后喷施1次(L-aftH-1)、绿比多高温处理前后各喷施1次(L-2)、浦绿高温处理前喷施1次(P-preH-1)、绿比多+浦绿高温处理前喷施1次(LP-preH-1);叶面肥高温处理前喷施1次(Y-preH-1)、常温空白对照(N-CK)、高温空白对照(H-CK)共8个处理,分析高温胁迫下草坪质量、黄叶率、叶绿素含量、净光合速率、蒸腾速率、过氧化产物、根系长度及根冠比等指标在不同处理下的变化,探讨了高温胁迫下绿比多对匍匐剪股颖的影响。结果表明:在高温胁迫15 d后,单喷绿比多的3个处理(L-preH-1、L-aftH-1、L-2)的草坪草质量显著高于、黄叶率显著低于LP-preH-1、Y-preH-1、P-preH-1处理(P<0.05),草坪草叶片具有较高的细胞膜稳定性和净光合速率,根系长度和根冠比亦较高。此外,L-preH-1处理草坪草的叶绿素含量和蒸腾速率显著高于L-aftH-1(P<0.05),成本控制上优于L-2。综上,单喷绿比多效果优于单喷浦绿、单喷叶面肥和浦绿+绿比多混喷,且高温前喷施对提高匍匐剪股颖耐热性更有利。

LBD is a new type of biostimulant based on amino acids and polypeptides,which can improve plant heat tolerance.However,the physiological mechanisms by which it works are not clear.This study examines the effects of LBD on creeping bentgrass(Agrostis stolonifera)turf quality,yellow leaf rate,chlorophyll content,net photosynthesis rate,transpiration rate,MDA content,root length,and the ratio of root and shoot under heat stress conditions that last for 15 d.The results showed that three LBD treatments:spraying LBD once before heat stress(L-preH-1),spraying LBD once after heat stress(L-aftH-1),and spraying LBD twice before and after heat stress(L-2),resulted in significantly higher turf quality and lower yellow leaf rate than did treatments involving spraying LBD and Primo MAXX together once before heat stress(LP-preH-1),spraying foliar fertilizer once before heat stress(Y-preH-1),and spraying Primo MAXX alone once before heat stress(P-preH-1)(P<0.05).In addition,the LBD treatments resulted in leaves that maintained a high level of cell membrane stability,higher net photosynthesis rate,increased root length,and an increased ratio of root and shoot.Furthermore,chlorophyll content and transpiration rate were significantly higher in the L-preH-1 treatment than in the L-aftH-1 treatment(P<0.05),and better than that in the L-2 treatment according to the cost control.Our data indicate that spraying LBD was more effective than spraying Primo MAXX,foliar fertilizer,or LBD+Primo MAXX;meanwhile,spraying LBD before heat stress was more advantageous for improving heat tolerance of creeping bentgrass.