Analysis On Mechanism Of Partial Ovule Abortion Of Eremurus Inderiensis (M. Bieb) Regel

Eremums inderiensis (M. Bieb) Regel was a kind of plant which belonged to the Eremums, Liliaceae. This genus had30species plants mainly distributed in Asia; there were species in China, and in our country Eremums inderiensis only distributed on fixed and semi fixed dune in the northern region of Xinjiang, it was a typical sabulicolous ephemeroid plant, They had great significance to improve and stable sandy. In natural populations of Eremums inderiensis, their fruit-setting, seed-setting rates were about30%and35%, they had obvious ovule abortion, limiting greatly population update of and expansion Eremums inderiensis. In this article, according to the positions of the flowers, the flowers on inflorescence axis were divided into three parts, basal, middle and top flowers, counting the fruit-setting and seed-setting rates of parts rachis respectively, therefore, thus discuss the abortion pattern of Eremums inderiensis. On the one hand, in the natural populations of Eremums inderiensis, artificial water supply and defoliation were conducted, pollen viability, stigma receptivity, and insect foraging behavior were the indicator, fruit-setting and seed-setting rates are gists, then discuss the environmental factors of abortion. On the another hand, the microsporogenesis, megasporogenesis and development of female and male gametophytes of Eremurus inderiensis were studied by paraffin-embedded sectioning technique, this study was to ascertain the key stage of ovule abortion in Eremums inderiensis, and observing cytological characters of the male and female organs. The following was the main results:1. Abortion patternEremums inderiensis (M. Bieb) Regel had racemes, the order of flowering was from base to the top along the axis in Eremurus inderiensis, the abortion rates increased in turn from the base to the top along the axis (base<middle<top); The flowers on top of axis got the highest abortion rate.2. Analysis on environmental factors of abortionIncreasing of sandy soil moisture content improved pollen viability, stigma receptivity, fruit-setting and seed-setting rates of Eremurus inderiensis; pollen viability, stigma receptivity, fruit-setting and seed-setting rates of small and defoliated plants was significant lower than large and undefoliated plants.3. Analysis on internal factors of abortionThere are six stamens, anthers with four locules. The anther wall grew into epidermis, endothecium, middle lamella and tapetum which was corresponds to glandular type from out side to inside. The meiosis of microspore mother cell belonged to simultaneous type and resulted in tetrahedral tetrad, the mature pollen grain was of the2-celled. Eremurus inderiensis has single ovary with three rooms and each room has4hemitropous ovules, the development of embryo sac was fritillaria type.Microspore abortions mainly occur before tetrad in Eremurus inderiensis, mainly included: Microspore mother cells had multiple nuclei, meiosis of microspore mother cells fail; Microspores can not flow freely from tetrad because the callose cann’t disintegrate normally; Microspores flew from tetrad can’t get a nucleus or get a small nucleus, part microspores can’t form the cytoderm; Tapetums disintegrate at the wrong period; a lot of empty mature pollens. Macrosporal abortions mainly occured from two nuclei embryo sac to ripe nuclei embryo sac, mainly included:nucelli and integuments disintegrate; Macrosporal cytoplasms and nuclei contract, then the nuclei disintegrated; The nuclei disintegrated not long after abruption; In the ripe nuclei embryo sac, egg cells, antipodal cells and polar-nuclei disintegrated asynchronously; Part ovules disintegrated directly left several empty ovaries.