| The agronomic traits, growth tip differentiation and microsporogenesis of Elytrigia intermedia, Elytrigia elongata and their hybrid F1are analyzed in this study. The aim is to discuss similarity and difference between Hybrid F1and parents with agronomic traits, the growth tip differentiation and microspore developmental aspects.It will provide a theoretical basis for breeding and hybrid breeding. The main results are as follows:(1) Hybrid F1are similar with Elytrigia intermedia on the leaves, root characteristics, ear length, ear width, the section number and tillering ability. It shows that the hybrid F1inherited characteristics of Elytrigia intermedia.(2) Growing tip differentiation of Hybrids F1and parents is a continuous process. The process could be divided into eight phases:vegetative phase, elongation phase, single ridge phase, spikelet protuberances phase, glume protuberances phase, floret differentiation phase, pistil and stamen formation phase and heading phase.according to morphological characteristics of growth tip in the differentiation process.(3) Growth tip differentiation speed of Hybrid F1and parents are different and still tillering during the plants jointing, which result in irregular plant heading, but the growth cone differentiation on each tiller has a strong regularity:the upper part of the spikelet is to the first development, and then gradually upward, downward development, the base of the spikelet is to the last development; the basic florets of each spike are to the first development, and then gradually upward development.(4) Microspore development process of Hybrid F1and parent is a continuous differentiation process. Hybrid and parent is not apparent anomalies in microspore development process. Hybrid F1could be observed that chromosomes have obvious adhesion phenomena and chromosome segregation is not synchronous. Bivalents are mainly observed in meiotic metaphase I, but univalents,trivalents and quadrivalent can also be observed. |
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