Effects Of Hydro-priming On Seed Germination And Seedling Growth Of Kiwifruit

Kiwifruit belongs to Actinidia of Actinidiaceae.Kiwifruit is a kind of perennial large deciduous and semi-deciduous vine,which can be used as medicine and food.It is widely planted all over the world at present.Seedling breeding is the premise and foundation for the sustainable utilization of kiwifruit resources.How to promote the seed germination more effectively and improve the seedling quality is the key to kiwifruit seedling breeding.Effects of Hydropriming on seed germination and seedling growth of three kiwifruit cultivars,kiwifruit Xuxiang,kiwifruit Hort16 A and kiwifruit Hongyang,were explored under alternant temperature of day and night,low-temperature stress and drought stress.Kiwifruit seed hydropriming system was constructed.The aim is to provide fundamental theory and technical support for the seedlings propagation utilization of kiwifruit.The main results are as follows:1.The essential biological characteristics of seeds from three kiwifruit cultivars were observed and determined.Their clarity was above 80%,the highest of which was Xuxiang(97.43%).There are significant differences in seed length and 1000 grain weight among varieties.The longest Hort16 A seed is 0.249 cm.The shortest Hongyang seed is 0.193 cm.The 1000-grain weight of Xuxiang,Hort16 A and Hongyang are 1.46 g,1.33 g and 1.26 g,respectively.The high seed viability of Xuxiang,Hongyang and Hort16 A are 98%,95% and 93%,respectively.2.Effects of Hydropriming on seed germination and seedling growth of different kiwifruit cultivars were explored under alternant temperature of day and night,low-temperature stress and drought stress.Results showed that the germination potential,germination index and critical threshold of different varieties were significantly increased,and germination time and half germination time were shortened in varying degrees.Besides,hydropriming can significantly increase the root length of seedlings and the biomass of seedlings to varying degrees.It can also be concluded that hydropriming effects under adverse conditions is more significant than that under alternant temperature of day and night.3.Effects of Hydropriming on relative conductivity of seeds from different kiwifruit cultivars were explored under alternant temperature of day and night,low-temperature stress and drought stress.Results showed that hydropriming treatment can reduce the conductivity of kiwifruit seeds.Effects of Hydropriming onthe content of soluble sugar,malondialdehyde and proline in seeds of different kiwifruit cultivars also were explored.It was found that hydropriming can reduce the content of soluble sugar and malondialdehyde,and increase the content of proline.These results indicated that hydropriming could repair the damaged cell membrane,increase the integrity of membrane structure,and reduce the leakage of cytoplasmic material,and improve the resistance of seeds to some extent.4.Effects of hydropriming temperature,hydropriming time,post-hydropriming culture temperature and dehydration treatment on seed germination were investigated.kiwifruit seed hydropriming system was constructed.The main factors affecting hydropriming effects were hydropriming temperature and post-hydropriming culture temperature.The optimal hydropriming conditions of Xuxiang were 5?hydropriming temperature,3d hydropriming time,cultural temperature 15? at night25? at day,no dehydration,the maximum critical threshold of 8.875,the seedling root length of 2.135 cm and the seedling dry weight of 13.54 mg.The optimal hydropriming conditions of Hort16 A were 5? hydropriming temperature,3d hydroprimingn time,cultural temperature 15? at night 25? at day,no dehydration,tthe maximum critical threshold of 2.159,the seedling root length of 1.578 cm and the seedling dry weight of 5.727 mg.The optimal hydropriming conditions of Hongyang were 5? hydropriming temperature,2d hydropriming time,cultural temperature 15?at night 25? at day,dehydration,the maximum critical threshold of 3.421,the seedling root length of 1.672 cm and the seedling dry weight of 5.311 mg.