桔梗雄性不育种质JXB-1的发现与鉴定

2006年在龙井市当地采集的3年生野生桔梗种源圃中发现雄性不育种质JXB-1个体，本研究对其生殖发育进行了进一步的实验验证。结果表明：JXB-1个体花的外观与正常的花比较无明显差异，但花药皱瘪；花药开裂，但无花粉粒散出，强行挤出来的花粉粒多数呈不规则型且无活力；套袋自交座果率为零，与30份不同桔梗种源杂交座果率为100%；经花药发育及小孢子发生过程观察，初步认为JXB-1花粉的败育主要发生在小孢子发育时期，JXB-1的绒毡层细胞过早解体，因而小孢子发育中途停止是败育的主要原因。用组织培养方法进行无性繁殖的JXB-1后代全部表现为雄性不育。初步研究结果表明JXB-1确属雄性不育，与其他种源有高度亲和力，可作为优良的育种材料。

Discovery and Identification of Male Sterility Platycodon grandiflorum Germplasm JXB-1

A male sterile germplasm JXB-1 was discovered at three-year-old wild Platycodon grandiflorum germplasms area in Longjing city in 2006 and its development and reproduction were further studied. The results showed that there was no obvious difference in flower’s outward appearance between JXB-1 and normal plant, but JXB-1 had shriveled and cracked anther with no microspore, forced anther with irregular and no activities, its self-pollination rate was zero and crosspollination rate was 100%. Anther and microsporogenesis observations showed that JXB-1 anther abortion mainly took place at tetrad stage because small spore growth was stopped for tapetum cells premature disintegration. Vegetative propagations of tissue culture for JXB-1 was all male sterile. It was preliminarily shown that JXB-1 was a male sterility germplasm, had high affinity with other germplasms and can be used as fine breeding material.