Whole-genome sequencing provides insights into the genetic diversity and domestication of bitter gourd(Momordica spp.)

Bitter gourd(Momordica charantia)is a popular cultivated vegetable in Asian and African countries.To reveal the characteristics of the genomic structure,evolutionary trajectory,and genetic basis underlying the domestication of bitter gourd,we performed whole-genome sequencing of the cultivar Dali-11 and the wild small-fruited line TR and resequencing of 187 bitter gourd germplasms from 16 countries.The major gene clusters(Bi clusters)for the biosynthesis of cucurbitane triterpenoids,which confer a bitter taste,are highly conserved in cucumber,melon,and watermelon.Comparative analysis among cucurbit genomes revealed that the Bi cluster involved in cucurbitane triterpenoid biosynthesis is absent in bitter gourd.Phylogenetic analysis revealed that the TR group,including 21 bitter gourd germplasms,may belong to a new species or subspecies independent from M.charantia.Furthermore,we found that the remaining 166 M.charantia germplasms are geographically differentiated,and we identified 710,412,and 290 candidate domestication genes in the South Asia,Southeast Asia,and China populations,respectively.This study provides new insights into bitter gourd genetic diversity and domestication and will facilitate the future genomics-enabled improvement of bitter gourd.

Studies on the Compositional Properties of Main Miben Series Pumpkin Varieties in Southern China

Pumpkin is among the most popular agricultural products in Southern China. To determine the important analytical properties(dry matter, total soluble sugar,dissolvable polysaccharides, mineral content, electricity conductivity, soluble solid content, fruit weight, fat, protein, fiber, pectin, β-carotene and edible rate) of pumpkin in Southern China, this study investigated the physical and chemical properties and texture of raw and steamed pumpkins of 13 Miben series varieties. Miben pumpkins were frozen at-40 ℃ for 24 h, or at-4 ℃ for 24 h, or were steamed for 15 min in boiling water to investigate the effect of different treatments on the textural change, and to reveal the texture and sensory properties of the different varieties. A total of 13 pumpkin varieties of Miben series CP1578, CP2116, XM2-2,Baimi II, Guangmi I, Guangzhouluxia, Jintong, Laojinhanzaoshu, Quanguanjixiang,Newzuhe III, V pumpkin, Zaoshutianmi and Daguomiben were involved in this study.The results showed that the Miben series pumpkins had significant difference in physical properties. The editable rate of Miben series pumpkins was higher than77%. Chemical properties varied among different varieties. Textures of pumpkin flesh after different processes were different. In the sensory assessment of Miben pumpkins, the varieties with overall quality scores more than 50 were Guangmi I, Laojinhanzaoshu, V pumpkin and Daguomiben, indicating that the four varieties all had excellent properties.

A Simple SSR-based Method for Purity Identification of Cucurbita moschata Hybrids

Aiming at solving the existing issues in purity identification of Cucurbita moschata hybrids by SSR, such as complex operation and difficult application in production practice, in this study, a simple SSR-based method was established for purity identification of Cucurbita moschata hybrids. By using the established simple method, without grinding, freezing, centrifugation and drying, the genomic DNA extraction process is shorter than 3 min. Compared with the conventional method, PCR detection system and silver staining in polyacrylamide gel electrophoresis of the established method are more time-saving and cost-saving. The whole detection process is shorter than 4 h, and 480 samples can be detected with this method by one person in one day. In addition, the detection result exhibits a coincidence rate of 99% with field identification. The simple SSR-based method established in this study can provide basis for large-scale rapid purity identification of Cucurbita moschata hybrids.