Flower Buds Cold-resistance Observation And Pollen Characteristics Of Almond

In this experiment,eight cultivated almond varieties in the natural wintering process were used as experimental materials,and the cold resistance physiological indexes of almond flower buds were determined,and the cold resistance was compared by fuzzy membership function method.Through the study of the changes of endogenous hormone content and the expression of cold-resistant genes in the flower buds of ’Zhipi 1’ and ’Zhipi 2’ during natural wintering,and the expression level of AcCBF1 gene on the almond buds by in situ hybridization initially.Finally,14 almond varieties and ’Wild almond’were used as experimental materials to determine the pollen quantity and pollen germination rate.The clustering relationship between the pollen morphology of almonds in different varieties was analyzed by electron microscopy and cluster analysis.The main conclusions are as follows:(1)All the cold resistance physiological indexes were negatively correlated with the natural wintering temperature.The lower the temperature,the greater the damage to the almond flower buds.Comprehensive evaluation of the cold resistance of 8 almond varieties during natural wintering is ’Sweet kernel peach almond’>’Neplus’>’Zhipi 2’>’Big almond’>’Zhipi l’>’Sonora’>’Maket’>’Mission’.(2)The contents of ABA,GA and JA in the flower buds of two almond varieties showed a trend of increasing first and then decreasing.The contents of IAA,BR and ZT did not change significantly with the change of temperature,so there was no significant correlation with the cold resistance of almond flower buds.Although the SA content shows a trend of increasing first and then decreasing,this has a certain relationship with the temperature change,but it is used to distinguish the cold resistance from the weakness.Therefore,the endogenous hormones that play an important role in the natural wintering of almond flower buds are ABA,GA and JA.(3)The expressions of AcCBF1,AcCBF2,AcDHN1,AcMADS3,AcSOD(Cu-Zn),AcPER9(POD)and AcPER9(CAT)in the flower buds of two almond varieties all showed a trend of increasing first and then decreasing with the change of temperature.In situ hybridization of two almond varieties collected at the same time using a sequence design probe on the AcCBF1 gene showed that the anthers were slightly different in degree of differentiation,and the ’paper 1’ differentiation was earlier and had entered During the tetrad period,’Paper 2’ differentiated late,most of them were in the pollen mother cell stage,but the AcCBF1 gene was highly expressed in the vascular vascular cells.(4)Among the 14 almond varieties and ’Wild almond’ in this study,the single pollen volume of the single anther was’Amannisha’,and the smallest pollen was ’Mission’;the pollen vigor increased with time,basically at 9h.The maximum value of germination is reached,and then it remains basically stable.The pollen vigor is the strongest,and the pollen vigor is the thickest shell.The pollen grains are arc-shaped at both ends.(P/E)Between 1.89 and 2.11,the equatorial view of most pollen grains is long spherical,and the polar view is mostly trilobed.The germination holes are slightly protruding at the angular end of the equatorial plane or flush with the corner end.With three-hole groove,the near-polar surface is shallow and narrow,and the near-equator surface is wide and deep,and the groove edge is not neat.The almond varieties ’Zhipi 2’ and ’Big almond’ have more pollen and higher pollen germination rate,which can be used as the preferred choice for almond pollination trees.