Research On The Biological Characteristics Of Stimulative Parthenocarpy Of Siratia Grosvenorii Fruit

Siratia grosvenorii is the medicinal and edible as the traditional Chinese medicine, it is only distributed in the north mountains of Guangxi province of China.Its Mogrosides V has application prospects and the demand id increasing.But some reasons limit the development of the industry.First,the land scarcity because of the suitable planting area is narrow,the land is unable to continue planting and growing and the male plants waste a lot of land, second the artificial pollination is heavy and the labor resources are scarce.Then the presence of the seeds caused great difficulties in extraction and utilization of Mogrosides V.Currently the triploid seedless seeds of Siratia grosvenorii solved the problem of seeds,but the fruit reduced in size and must be artificially pollinated, plant efficiency is much lower than the seed varieties,can not widely cultivated.This study use plant growth regulators to stimulate the female flowers of Siratia grosvenorii to get parthenocarpic fruits,this technology solve the problems in production,including the male plants cover wide area and artificial pollination, increase the production of fruits, significantly reduce the costs and difficulty.This is a beneficial found of Siratia grosvenorii cultivation,its application changed the traditionally cultivation patterns which must be artificial pollinated in order to get the fruit before,end the era of heavy artificial pollination. We study the biological characteristics,anatomical features,changes of endogenous hormone and gene expression profiles of the parthenocarpy fruit of Siratia grosvenorii,provide the basis for the formation mechanism of stimulative parthenocarpic of Siratia grosvenorii. The results are described as follows:1. The development of stimulative parthenocarpic of Siratia grosvenorii fruit: parthenocarpic fruit growth is consistent with the normal growth and development of fruit after pollinate,the fruit grow fast from 3 days to 20 days,then grow slowly after 30 days,ripe fruits are middle or large size,with small amount seeds,content of Mogrosides V is 1.47%,has no significant difference with the pollination fruit, and easy to dry and good help for transport and storage.2.Anatomical characteristics of parthenocarpic fruit are these:embryo of parthenocarpy fruit does not grow after growth regulators induced,only the integument form the seed coat,the mature seed has only coat.The pulp cells are swelling,earlier and bigger than the pollinated fruit after 3 day.3.Variation of endogenous hormone within parthenocarpic fruits:the content of IAA is decreased then increased, and the parthenocarpy fruit has the higher content than pollinated fruit outside of 10 days and 20 days.GA content is increased then decreased, but parthenocarpic fruit has the higher peak height compared with pollinated group(except 1 days), that respectively in 3 days and 5-10 days. ZT content drop then rose, ZT content is higher in parthenocarpic fruit than that in pollinated fruit brfore 10 days, but lower in 15 days and 20 days.ABA content also drop first then rose, and the parthenocarpic fruits have the lower level from 5 days to 20 days but rapid increase after 30 days.4.We obtained 352,757,748 reads and 69,047 unigenes in the transcriptome sequencing of early development of fruit by Solexa high-throughput sequencing technology.Discoved the the related unigene of related hormone of parthenocarpic fruit in early development are 716,including 204 unigene related to auxin,67 unigene related to GA,177 unigene involved in cytokinin,140 unigene involved in brassinosteroids and 128 unigene involved in ethylene,and all known genes have found. In addition, we also found 121 unigene of Cytochrome P450 gene involved in ABA unigene are 81,involved in salicylic unigene are 78,involved in methyl jasmonate unigene are 87. Then we also found transcription factors unigenes are total 406, including the MYB transcription factor, MYC, RAX1, WRKY, HB29, HBP-lb, BZIP, GATA, NAC, B3 domain-containing transcription factor, bHLH, etc. These structural genes and regulatory genes unigene is the important genetic resources for the further study parthenocarpy in the future.5.Compared with the sample of Od,1831 genes were up regulated and 2768 genes were down in 1d sample of parthenocarpy,2776 genes were up regulated and 2299 genes were down in 3d sample of parthenocarpy.Then we found 26 genes associated with the initial development of parthenocarpy for future full-length gene cloning and functional verification.6.To verify these 26 genes by qRT-PCR experiments,the results showed that the relative expression patterns were generally accessible with the transcriptome expression pattern and revealed the AUX/IAA14,GA20ox,IPT,CYP735A,ACO, CYP85A1,CYCD5-1,BAK1, BRI1,BSK,CHS and MADS-box may be the key enzymes genes of fruit early developing of parthenocarpic fruit of Siratia grosvenorii,these results provide the reference for the further ways to regulate the expression of these genes and improve the method of the hormone treatment in the cultivation of Siratia grosvenorii.