Study On The Regulation Of Reproductive Growth Of Calotropis Gigantea And The Development Of Akund

Akund is a kind of available natural vegetable Fibers, grows on the seeds of the Calotropis gigantea, that is a new discovery, which has big hollow degree, good gloss characteristics. Previous study found that it has lots of flowering but low seed-set, that makes the akund production decreases. In this study, we identified different types of Calotropis gigantea, discovered female and male gametophtes development, and analysis the effect of pollen germination in vitro; then studied the development of akund. Main results as follows:1. Based on the external morphological characters and molecular genetics, identified different types of Calotropis gigantea, the result shows that:different types of Calotropis gigantea has different characteristics. Chromosome number is 22,7 ISSR primers amplification results showed that the polymorphism locipercentage is 83.8%.2. Discovered the relationship between microspore and megaspore development and buds morphology. Stamen developed earlier than pistil. Successive cytokinesis in the microspore mother cells (MMCs) follows meiosis, 2 layers glandular tapetum, secretory structure, microspore gathered into pieces, the mature pollen grain random arrangement. Mature embryo sacs belonged to polygonum type sac, amphitropous ovule. Meiosis of megaspore mother cell formed a linear tetrad. The mature embryo sac has secondary polar nucleus.3. H3BO3, Ca2+, Mg2+ and sucrose in the culture medium were needed for pollen germination and pollen tube growth in a certain range of concentration, but not for higher or lower. The results of the orthogonal tests show that, the best liquid medium combination of pollen germination is 350 mg/L Ca(NO3)2·4H2O +60 mg/L H3BO3+150 mg/L MgSO47H2O+15% sucrose.4. According to the Calotropis gigantea seed color divided the five fiber maturity. Based on the seed germination and fiber uniformity index, upper half mean, length micronaire, elongation, fibre strength, the result shows that there is no significant difference between the mature fiber and the yellow seed fiber, so the fiber can be harvested. Akund mature period in late July to the middle of October, fiber length and fruit length were positively correlated, same as the fruit wide.