不同育性枸杞小孢子减数分裂过程及其结构特征差异分析OA

[Objective]The study aims to systematically compare the correlation between anther morphol-ogy and microspore development in the fertile line'Ningqi 1'and the male sterile line'Ningqi 5',identify the critical stage of microspore abortion,and reveal the differences in ultrastructure between the two lines,thereby providing a theoretical basis for clarifying the molecular regulatory mechanism of male sterility in L.barbarum L..[Method]Flower buds at different developmental stages of the fertile line'Ningqi 1'and the sterile line'Ningqi 5'were used as experimental materials.Phenotypic observations and comparative analyses of micro-spore development were performed.The meiotic process of pollen mother cells and the structural characteristics of microspore abortion were analyzed using the squash methods and transmission electron microscopy.[Result]During the meiosis in pollen mother cells of both lines,chromosome behavior was normal,yielding normal tet-rads.Tetrads in'Ningqi 1'developed into fertile pollen grains filled with starch granules and lipid droplets.In contrast,microspores in'Ningqi 5'underwent progressive shrinkage,deformation,and disintegration within the callose.Ultrastructural analysis revealed that microspores in'Ningqi 5'could form a primary pollen exine within the callose,but the cytoplasm adjacent to the cell wall gradually vacuolated,the nuclei condensed,and eventually the microspores completely disintegrated,leading to pollen abortion.Additionally,the cell walls of the tapetum cells in'Ningqi 5'exhibited abnormal thickening,which indicated abnormal programmed cell death.[Conclu-sion]Anther abortion in sterile lines occurs at the tetrad stage,and the failure of callose degradation around mi-crospores is the direct cause of abortion.It is speculated that abnormal development of tapetum cells results in callase deficiency or insufficient enzyme activity,thereby preventing the release of tetrad microspores and ulti-mately causing male sterility.