The use of R in photosynthesis research.

R is one of the most commonly used analytical tools in the plant sciences. To identify key trends in general reported R use and patterns in photosynthesis research, we explored the frequency of R use in 2966 articles published in the 377 journals with 'photosynthesis' in the title from 2010 to 2019 using the Web of Science search. Solutions provided by each R package cited in the articles or online sources was recorded and classified. The percentage of research articles reporting R use increased linearly from 3.6% in 2010 to 12.5% in 2019. The three main categories of R package solutions were 'general statistical calculations and graph packages' (G); 'photosynthesis special-purpose packages' (S); and 'genetic and evolutionary packages' (E). The top five R packages cited were nlme (G), lme4 (G), multcomp (G), plantecophys (S), and ape (E). The increasing popularity of R use in photosynthesis research is due to its user-friendly and abundant open-source codes online for handling specific issues, particularly in fitting photosynthesis models. These findings are limited by the number of articles and online sources, but they reveal a significant increase in usage in photosynthesis research over the past decade and have a bright prospect in the future.

Manglietia pubipedunculata (Magnoliaceae), a new species from Yunnan, China.

A new species, Manglietia pubipedunculata Q. W. Zeng & X. M. Hu (Magnoliaceae) is described and illustrated from Yunnan, China. In addition to macromorphological examination, we comparatively studied on micromorphology of leaf epidermis, leaf structure, and epidermal cell on the sclerotesta. This new species is similar to M. kwangtungensis in terms of having dense pubescence, however, their pubescence are quite different. Manglietia pubipedunculata has appressed, compressed, shorter and sparser pubescence consisting of single or two cells. Moreover, it differs from M. kwangtungensis by showing shorter and thicker peduncles, longer styles, basal carpels covered with sparsely brown appressed pubescence, and more ovules per carpel. Furthermore, the new species has thinner leaves, brown and rugged surfaces on sclerotesta, and the alveolate cell pattern consisting of pentagon or hexagon cells with papilla on secondary cell wall under the observation by SEM. The phylogenetic analysis from two nuclear PHYA and LEAFY and chloroplast trnH-psbA sequences of 11 taxa reveals that M. pubipedunculata is a distinct species.