Docynia has been treated as a separate genus or merged into Cydonia or Docyniopsis. Our phylogenomic evidence from 797 single-copy nuclear genes and plastomes confirmed the sister relationship between Docynia and Docyniopsis. By integrating the phylogenomic and morphological evidence, we propose to accept a broad generic concept of Malus and merge Docynia into Malus. Three new combinations are also made here: Malus delavayi (Franch.) B.B.Liu, M. indica (Wall.) B.B.Liu and M. longiunguis (Q.Luo & J.L.Liu) B.B.Liu.

Root exudates from Chinese celery (Apium graveolens) and Chinese cabbage (pak choi, Brassica chinensis) plants treated by prometryn, an herbicide, were qualitatively and quantitatively investigated and compared under hydroponic cultivation. Prometryn and its metabolites released into the nutrient solution were analyzed by ultra-performance liquid chromatograph coupled with orbitrap mass spectrometer to investigate whether this xylem-mobile herbicide is exuded from the roots. The results showed that celery and pak choi had different root exudation profiles. Celery metabolized prometryn to prometryn sulfoxide and released both compounds from the roots. In contrast, pak choi barely metabolized or actively released prometryn from the roots. The concentration of prometryn sulfoxide released from celery after 96 hr was 21 µg/L, which was nearly one-third that of released prometryn. Our results indicate that the root exudation and translocation of xylem-mobile herbicides could be significant in plants and are highly species dependent compared with phloem-mobile herbicides.

Cardiocrinum giganteum is an endemic species of east Asia which is famous for its showy inflorescence and medicinal bulbs. Its inflorescence is a determinate raceme and the flowers bloom synchronously. Morphological observation and time-course transcriptomic analysis were combined to study the process of inflorescence and flower development of C. giganteum. The results show that the autonomic pathway, GA pathway, and the vernalization pathway are involved in the flower formation pathway of C. giganteum. A varied ABCDE flowering model was deduced from the main development process. Moreover, it was found that the flowers in different parts of the raceme in C. giganteum gradually synchronized during development, which is highly important for both evolution and ecology. The results obtained in this work improve our understanding of the process and mechanism of inflorescence and flower development and could be useful for the flowering period regulation and breeding of C. giganteum.

In this comprehensive study, we conducted extensive taxon sampling and performed phylogenomic analyses based on plastome and nuclear ribosomal DNA (nrDNA) datasets. We employed multiple inference methods, including concatenated and coalescent-based strategies, to generate an accurate phylogeny of the woody Rosaceae genus Pourthiaea . The nrDNA phylogeny of Pourthiaea strongly supported three major clades, which were consistent with morphology. However, the plastid tree provided an alternative phylogenetic topology, indicating cytonuclear discordance. Frequent hybridizations between and among the species of Pourthiaea could explain the cytonuclear discordance. Considering the evidence from morphology and phylogenomic data, we propose a new infrageneric classification for Pourthiaea , consisting of three sections: P. sect. Pourthiaea , P. sect. Amphidoxae B.B.Liu, and P. sect. Impressivenae B.B.Liu.