Am J Bot. 1997 Nov;84(11):1502.
The tassel seed mutations ts4 and Ts6 of maize cause irregular branching in its inflorescences, tassels, and ears, in addition to feminization of the tassel due to the failure to abort pistils. A comparison of the development of mutant and wild-type tassels and ears using scanning electron microscopy reveals that at least four reproductive meristem types can be identified in maize: the inflorescence meristem, the spikelet pair meristem, the spikelet meristem, and the floret meristem. ts4 and Ts6 mutations affect the fate of specific reproductive meristems in both tassels and ears. ts4 mutants fail to form spikelet meristems from spikelet pair meristems. Ts6 mutants are delayed in the conversion of certain spikelet meristems into floret meristems. Once floret meristems are established in both of these mutants, they form florets that appear normal but fail to undergo pistil abortion in the tassel. The abnormal branching associated with each mutant is suppressed at the base of ears, permitting the formation of normal, fertile spikelets. The classification of the different types of reproductive meristems will be useful in interpretation of gene expression patterns in maize. It also provides a framework for understanding meristem functions that can be varied to diversify inflorescence architectures in the Gramineae.
玉米的 ts4 和 Ts6 突变导致其花序、雄穗和穗轴的不规则分枝，以及由于雌蕊败育而导致雄穗的雌性化。通过扫描电子显微镜比较突变体和野生型雄穗和穗轴的发育，可以鉴定出玉米中至少有四种生殖分生组织类型：花序分生组织、小穗对分生组织、小穗分生组织和小花分生组织。ts4 和 Ts6 突变影响雄穗和穗轴中特定生殖分生组织的命运。ts4 突变体从小穗对分生组织中不能形成小穗分生组织。Ts6 突变体在某些小穗分生组织向小花分生组织的转化中延迟。在这两种突变体中一旦形成小花分生组织，它们就会形成外观正常的小花，但在雄穗中不能进行雌蕊败育。与每个突变体相关的异常分枝在穗轴的基部受到抑制，允许形成正常的、可育的小穗。不同生殖分生组织类型的分类将有助于解释玉米中基因表达模式。它还为理解分生组织功能提供了一个框架，这些功能可以改变禾本科植物花序结构的多样性。
