Preliminary Studies On The Seeds Abortion Of White Cucumber (Cucumis Sativus L.)

Cucumber (Cucumis sativus L.) is an important vegetable. With the improvement of people's living, they need not only better quality but also more variety of colors for cucumber. White cucumber is gradually favoured. In course of white cucumber breeding, the yield of its seed is lower because of shrunken grains, which brings on higher price of the seeds of white cucumber and blocks the spread.The study aims to find the main factors related to embryo developing which lead to the abortion seeds of white cucumber, with the contrast between three cultivars of white cucumber which seeds is aborted seriously and one cultivar of green cucumber which seeds develop normally. The study was done from the view of embryology and morphology. The main results were as follows:1. Pollen energy of the white cucumber is lower than that of green cucumber.2. Some microspore tetrads which conglutinated with each other formed complex microspore tetrads on white cucumber. At the phase of monomicrospore , some microspores wall were crimpled and their membrane were pitted and irregular. It was observed that the microspores in some anther of white cucumber were so crowd that some of them were difficult to develop normal pollen grains. The tapetum in the anther wall of white cucumber was developed as well as that of green cucumber.3. It was also observed in white cucumber that there were multipolar nucleus-like in the center of mature embryo sac, nucellus cells were dispersed and the edge of some megaspore sacs were irregular.4. In the early globular embryo phase of white cucumber, endosperm in which the cells were vacuolated in advance and were easily exposured like glass under microscope due to light-dyed developed abnormally. The inclusion in the endosperm cells was degraded ahead. Subsequently the endosperm cells were broken down and the globular embryo was stopped to develop.5. The seed plumpness on white cucumber was negative correlation with its fruit diameter and weight, especially fruit diameter. The seed plumpness was positive correlation with the fruit index and had no linearity with the fruit length. It's size should be moderate and its shape should be normal when the fruit of white cucumber was reserved seed for planting.