| Seashore paspalum is a perennial warm-season turfgrass that is used both in turf and pasture.It is widely used in many tropical and subtropical areas around the world due to its dark green color,strong root system and excellent salt tolerance.Although seashore paspalum has strong tolerance to long-term water shortage in the dry season,the drought resistance of different germplasms are quite different.In this study,56 materials of seashore paspalum were used as research objects and two kinds of widely-used warm-season turfgrass were used as controls to observe the dynamic changes in morphology and physiological characteristics under complete water control conditions.The drought resistance of different germplasms was investigated and their physiological mechanisms of drought resistance were discussed.(1)There were significant changes in the pertencage of withered leaves and turfgrass appearance quality of turfgrass under complete water control conditions in the greenhouse.The two best materials(647902 and 647892),and two worst materials(647916 and 647917),along with the controls,Zoysia matrella and Cynodon transvaalensis X C.dactylon,and SP005,an autonomously-selected material were selected to do the further comparison and analysis.Furthermore,the cluster analysis was performed based on the turfgrass appearance quality of all tested materials under fully control of water for 61 days.Based on the above results,the drought-tolerant material 647902 and drought-sensitive material 647916 were determined to do the further analysis.(2)The screened two seashore paspalum materials and local cultivar SP005 were drought-treated for 15 days and the relative soil water content(SWC),turfgrass appearance quality,relative growth rate the percentage of withered leaf,leaf relative water content(RWC),electrolyte leakage of leaves and roots,the dry weight of aboveground and underground tissue,and soluble sugar contents in leaves,stems,and roots were determined.The results indicated that SP005 and 647902 maintained higher turfgrass appearance quality,RWC and relative growth rate compared with 647916 under the same level of drought stress.In addition,the former materials had fewer withered leaves,and less electrolyte leakage of leaves and roots,which revealed that they could maintained higher membrane stability.Furthermore,SP005 and 647902 had higher soluble sugar contents in leaves,stems and roots than 647916,indicating that they had better osmotic adjustment ability.The 647902 was performed better than the SP005 in maintaining turf quality,the percentage of withered leaf,and leaf relative water content.In summary,the rank of drought resistance of the three materials was 647902>sp005>647916.This study provided a theoretical foundation for the breeding of drought resistant seashore paspalum,and for the improvement of the water-saving irrigation techniques. |
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