Draft genome of the famous ornamental plant Paeonia suffruticosa.

Tree peony (Paeonia Sect. Moutan) is a famous ornamental plant, with huge historical, cultural, and economic significance worldwide. In this study, we reported the ~13.79 Gb draft genome of a wide-grown Paeonia suffruticosa cultivar "Luo shen xiao chun," representing the largest sequenced genome in dicots to date. Phylogenetic analyses based on genome sequences demonstrated that P. suffruticosa was placed as sister to Vitales, and they together formed a clade that was sister to Rosids, weakly supporting a relationship of ((Saxifragales and Vitales) and Rosids). The identification and expression analysis of MADS-box genes based on the genome assembly and de novo transcriptome assembly of P. suffruticosa revealed that the function of C class genes was restricted in flower development, which might be responsible for the stamen petalody in tree peony cultivars. Overall, the first sequenced genome in the family Paeoniaceae provides an important resource for the origin, domestication, and evolutionary study as well as cultivar breeding in tree peony.

[Effects of tillage pattern on the flag leaf senescence and grain yield of winter wheat under dry farming].

A field experiment was conducted to study the effects of different tillage patterns, i.e., deep plowing once, no-tillage, subsoiling, and conventional tillage, on the flag leaf senescence and grain yield of winter wheat, as well as the soil moisture and nutrient status under dry farming. No-tillage and subsoiling increased the SOD and POD activities and the chlorophyll and soluble protein contents, decreased the MDA and O2(-.) contents, and postponed the senescence of flag leaf. Under non-tillage and subsoiling, the moisture content in 0-40 cm soil layer at anthesis and grain-filling stages was decreased by 4.13% and 6.23% and by 5.50% and 9.27%, respectively, and the contents of alkali-hydrolysable N, available P, and available K in this soil layer also increased significantly, compared with those under conventional tillage. Deep plowing once decreased the moisture content and increased the nutrients contents in 0-40 cm soil layer, but the decrement and increment were not significant. The post-anthesis biomass, post-anthesis dry matter translocation rate, and grain yield under no-tillage and subsoiling were 4.34% and 4.76%, 15.56% and 13.51%, and 10.22% and 9.26% higher than those under conventional tillage, respectively. It could be concluded that no-tillage and subsoiling provided better soil conditions for the post-anthesis growth of winter wheat, under which, the flag leaf senescence postponed, post-anthesis dry matter accumulation and translocation accelerated, and grain yield increased significantly, being the feasible tillage practices in dry farming winter wheat areas.