Study On Biological Characteristics And Drought Resistance Of Different Ecological Types Of Cerasus Humilis

In this test,5 different types of Cerasus humilis were used as test materials.By studying its phenological period,new tips growth dynamics,fruit development dynamics,and changes in physiological parameters such as gas exchanges,chlorophyll content,membrane permeability,antioxidant enzyme activity under drought stress.And on the 12th day of stress,the significance analysis of each variety was compared to determine the growth and development habit of the Cerasus humilis and explore the drought resistance mechanism of the Cerasus humilis.The phenological stages of different types of Cerasus humilis and their similarities and differences during growth were compared,the drought resistance of different types of Cerasus humilis was identified,and a part of the index system for drought resistance identification of common Cerasus humilis was established.The main results of this study were as follows:1.The phenology period of Cerasus humilis in 2019 is 147-172 days,of which the flowering period is 6-16 days,the new tips growth period is about 101 days,and the fruit growth period is 107-120 days.Cerasus humilis's new shoot growth shows a 's' curve.The roughness of the new tips grew fastest on June 21 and the length of the new tips grew fastest on June 11.The growth dynamics of the Cerasus humilis fruit are in a double 's' curve.After the Cerasus humilis fruit enters the expansion stage,the lateral diameter of the fruit increases significantly faster and eventually exceeds the longitudinal diameter.The branches of Ning Cerasus humilis were tall and thick,and the length and thickness of new tips were significantly larger than those of other varieties.The branches of 'Mongolian' C.erasus humilis were slender and the thickness was significantly smaller than that of other varieties.Although the flowering period of 'Mongolian' Cerasus humilis and Ning Cerasus humilis two kinds of narrow-leaf prunus is 8-10 days later than the three kinds of broad-leaf Cerasus humilis,the fruit growth period is shorter than that of broad-leaf Cerasus humilis 10-13 days.'Mongolian' Cerasus humilis and Ning Cerasus humilis fruits matured earlier than Nongda4,Nongd6,Nongda7 for 7-15 days,and belong to early maturing varieties.2.Under drought stress,the photosynthetic rate,transpiration rate,and stomatal conductance of the Cerasus humilis blade decreased as the stress level deepened.Intercellular CO2 concentration showed a trend of first decrease and then increase,and the chlorophyll content showed a trend of first increase and then decrease.The relative conductivity showed a gradual upward trend,and the MDA content increased first and then decreased.The activity of SOD showed a downward trend,and the activity of POD gradually increased.3.On the 12th day of drought stress,the photosynthetic rate,water use efficiency,and SOD activity of 'Mongolian' Cerasus humilis were significantly higher than those of other varieties,and the content of MDA was significantly lower than that of other varieties.The relative conductivity of'Mongolian' Cerasus humilis and Nongda7 was significantly lower than other varieties.POD activity of Nongda7 was significantly higher than other varieties.This shows that 'Mongolian' Cerasus humilis and Nongda 7 have stronger resistance to moderate and severe drought stress.