Studies On The Law Of Endosperm Subtraction And The Microstructure In Micro-edosperm Super High Oil Corn

The test was conducted from 2007.2～6 (spring seeding) to 2007.8～12 (autumn seeding) with the high oil maize 115 as control sample. The process of accumulation of fresh weight and dry weight and their corresponsive oil content in kernel, embryo, endosperm, seed capsule, and the microstructure of kernel, during the kernel filling in micro-endosperm super high oil corn were researched; the main results were as follows:1. The micro-endosperm super high oil corn presented the phenomena of growth and decline and it was the very significant difference with the high oil maize 115, during the process of accumulation dry weight. During spring seeding, with the increasing of pollination days, dry kernel weight was increasing and reached the peak 27th after pollination and then became stable. Similarly the dry weight of embryo, reached the peak 42nd after pollination and then became stable. Dry endosperm weight always increasing and reached the peak 27th after pollination, and then began decrease, 37th after pollination the decrease process was finished and became stable.During the autumn seeding, dry kernel weight always increasing and reached the peak 34th after pollination, and then became stable. Dry embryo weight always increasing and reached the maximum 52nd after pollination, and then became stable. Dry endosperm weight always increasing and reached the maximum 36th after pollination, and then begins decrease, 52nd after the decrease process was finished and became stable.2. The analyze of grain filling growing of micro-endosperm super high oil corn, Compared to high oil maize 115 revealed that the active grain filling period and the exponential growth phase were shorter. The analysis of kernel endosperm cells multiplication in micro-endosperm super high oil corn revealed that the endosperm cells were less. Concerning the two varieties, the path analysis of kernel filling process, about the correlation between the grain filling speed, grain filling duration, the endosperm cell filling rate, and dry kernel weight, revealed that dry kernel weight, in the two varieties, receive the influence of the endosperm cell filling rate and grain filling duration. But for the micro-endosperm super high oil corn, the variation of dry kernel weight also had another more important reason. This awaits further studied.3. The observation of microstructure of kernel during the grain filling, Compared to high oil maize 115, revealed that the four periods of the grain filling increasinged basically with the dry weight and fresh weight. The decreasing period was from 32nd to 47th after pollination, about 15 days. During the grain filling process, starch was accumulated mostly in endosperm, but it was not important; protein and fat were accumulated mostly in embryo and aleurone layer. Through observing crosscut and slitting slice, the ratio between crosscut and slitting slice area of embryo was larger. The shape of embryo of crosscut section was similar as a triangle or ladder with the less top and larger bottom. But the shape of slitting slice of embryo was different, enlarged at the embryo proper low-end suspensor, the middle part reduced and sutellum at apex was bending and hypertrophy. Starch content was less, in the later period; the endosperm cytoskelet was destroyed, while the inner endosperm cells were dead. The kernel aleurone layer thickness and width increased with days after pollination. The analysis of kernel aleurone layer indicated that there was no variation 47 days after pollination. The kernel aleurone layer thickness of crosscut on micro-endosperm super high oil corn was longer than on high oil maize 115. But the kernel aleurone layer width of crosscut was not different.4. The oil percentage of kernel and endosperm in micro-endosperm super high oil corn was much higher than in high oil maize 115, but the oil content of mature embryo of the later was higher than the former. The analyze of the simple correlation for kernel percent oil during maturing period, revealed the significant and positive correlations between, kernel percent oil and dry embryo weight, embryo and kernel ratio, embryo and endosperm ratio, kernel aleurone layer thickness. The same analyze revealed also the significant negative correlation between dry kernels weight, dry endosperm weight, number of endosperm cells, While the cell number of aleurone layer and dry seed capsule were not significant.