The Phoebe genome sheds light on the evolution of magnoliids

Lauraceae includes the genus Phoebe,and the family is linked to the evolution of magnoliids.We sequenced the genome of Phoebe bournei Nanmu.The assembled genome size was 989.19 Mb,with a contig N50 value of 2.05 Mb.A total of 28,198 protein-coding genes were annotated in P.bournei.Whole-genome duplication(WGD)analysis showed that Lauraceae has experienced two WGD events;the older WGD event occurred just before the divergence of Lauraceae and Magnoliales,and the more recent WGD was shared by all lineages of Lauraceae.The phylogenetic tree showed that magnoliids form a sister clade to monocots and eudicots.We also identified 63 MADS-box genes,including AGL12-like genes that may be related to the regulation of P.bournei roots and FIN219-like genes encoding GH3 proteins,which are involved in photomorphogenesis.SAUR50-like genes involved in light signal-mediated pedicel or stem development were also identified.Four ATMYB46-and three PtrEPSP-homologous genes related to lignin biosynthesis were identified.These genes may be associated with the formation of straight trunks in P.bournei.Overall,the P.bournei reference genome provides insight into the origin,evolution,and diversification of Phoebe and other magnoliids.

Separation of Insecticidal Ingredient of Paecilomyces cicadae (Miquel) Samson

In this study, the insecticidal active substance of the fruiting body of Paecilomyces cicadae （Miquel） Samson that can kill the larvae of Plutella xylostella （Lepidoptera： Plutellidae） was isolated and purified by combined separation with biology experiments for the first time. By means of bioactive guided isolation of 40% ethanol-H2O, dichloromethane, ethyl acetate, n-butyl ethanol, macroporous adsorption resin column, high performance liquid chromatography, and sephadex A-20 column, the insecticidal active compound was purified,and a white powder compound was obtained. The compound was active against the third instar larvae ofP. xylostella in 24, 48, and 72 h at the concentration of 10.0 mg mL-1 with a corrective mortality of （95.1 ± 1.8）, （97.7 ± 1.6）, and （99.1 ± 1.7）%, respectively. The compound was strongly sensitive to the larvae. It was stable at acid environment, and was not sensitive to pepsin, and other chracteristics were studied.

Frequent germplasm exchanges drive the high genetic diversity of Chinese-cultivated common apricot germplasm

The genetic diversity of germplasm is critical for exploring genetic and phenotypic resources and has important implications for crop-breeding sustainability and improvement.However,little is known about the factors that shape and maintain genetic diversity.Here,we assembled a high-quality chromosome-level reference of the Chinese common apricot‘Yinxiangbai’,and we resequenced 180 apricot accessions that cover four major ecogeographical groups in China and other accessions from occidental countries.We concluded that Chinese-cultivated common apricot germplasms possessed much higher genetic diversity than those cultivated in Western countries.We also detected seven migration events among different apricot groups,where 27%of the genome was identified as being introgressed.Remarkably,we demonstrated that these introgressed regions drove the current high level of germplasm diversity in Chinese-cultivated common apricots by introducing different genes related to distinct phenotypes from different cultivated groups.Our results highlight the consideration that introgressed regions may provide an important reservoir of genetic resources that can be used to sustain modern breeding programs.

Effect of Indole Butyric Acid on the Transportation of Stored Calcium in Malus hupehensis Rhed. Seedling

Calcium （Ca） plays an important role in the metabolism of higher plants. Recently, research on Ca^2＋ in plants has been focused especially at the cellular and molecular levels. Uptake, transport, and distribution are also very important for Ca to accomplish its function at the whole-plant level. In this experiment, one-year-old apple seedlings （M. hupehensis Rehd.） were investigated to determine the distribution of stored Ca, the different forms of Ca, and Ca^2＋-ATPase activity after treatment with indole butyric acid （IBA）. The results showed that the total Ca measured in mature leaves and Ca^2＋- ATPase activity in tender leaves were higher compared with those in the control （CK）. Calcium nitrate and calcium chloride （ALe-Ca） and calcium phosphate and calcium carbonate （HAC-Ca） decreased in both mature leaves and shoots, whereas water-soluble calcium （H2O-Ca）, calcium pectate （NaCl-Ca）, and calcium oxalate （HCl-Ca） increased. The percentage of active calcium, calcium pectate, and water-soluble calcium increased, whereas the percentage of calcium phosphate and calcium carbonate decreased. When treated with IBA, calcium fractions and percentage of the different forms of Ca was enhanced in 40 part per million （ppm） IBA compared with 20 ppm IBA and water. The results indicated that IBA increased the percentage of both active calcium （NaCl-Ca and H2O-Ca） in tender shoots and boosted the transportation of stored Ca in plants. IBA promoted Ca^2＋-ATPase activity and Ca^2＋ uptake in tender shoots of M. hupehensis. It can improve the total Ca contents and the relative percentage of Ca.

The Cymbidium goeringii genome provides insight into organ development and adaptive evolution in orchids

Cymbidium goeringii is one of the important ornamental orchids,but its high-quality genome has not been previously published.Here,we report a chromosome-level genome of C.goeringii and report the gene family expansion,and contraction of the C.goeringii genome and the regulation mechanism of MADS-box genes in floral organ development.We constructed the pathways of carotenoids and anthocyanins that contribute to the different flower colors of C.goeringii and the metabolic pathways of the main components of flower fragrance.Moreover,we found the genes that regulate colourful leaves and analyzed the resistance genes involved in the adaptive evolution of C.goeringii.Our results provide valuable genomic resources for the improvement of orchids and other ornamental plants.