Comparative Analysis Of Cucurbitaceae Genome Formation

In this project,7 sequenced Cucurbitaceae crops,such as melon and wax gourd,are taken as the research objects.Using comparative genomics and data statistics,the complex genome structure and gene family evolution after polyploidy are reanalyzed,and the important genomic resources and new development of Cucurbitaceae are obtained.(1)The largest genome structure of Cucurbitaceae was analyzed,and the CCT range was determined.For the first time,the karyotype of 15 chromosomes of Cucurbitaceae common ancestor was reconstructed,and found the wax gourd and melon was revealed to be conservative,which can be used as reference;(2)using the identified chromosome rearrangement and collinearity,and combining with the similarity of DNA fragments,the homologous regions produced by different events are distinguished,and the largest homologous alignment of Cucurbitaceae is constructed;(3)using the nuclear density function,Ks was analyzed,a mathematical method was constructed to measure the time of the important nodes.It was inferred that squash appeared 2700?3100 years ago,and its recent WGD occurred 2500?2800 years ago;(4)based on the phylogenetic distance,and the possible gene conversion were identified.It was found that the number of homologous quartets constructed by Cucurbitaceae was small,but its rate was higher than that of grass;(5)through the analysis of gene family cluster,there were 1249 gene families in all Cucurbitaceae,and new generation and loss of gene families were identified.The polygalacturonase and bitter gene in Cucurbitaceae was analyzed,and their amplification mechanisms are mainly tandem repeat.The research of this project is of great significance to the understanding of Cucurbitaceae genome structure,evolution history and gene function innovation,and provides the support of genomics in Cucurbitaceae gene identification and molecular breeding.Figure 22;Table 4;Reference 67...