Rubber latex yield is affected by interactions between antecedent temperature, rubber phenology, and powdery mildew disease

Rubber (Hevea brasiliensis) latex production is crucial to the local economy, yet Xishuangbanna's climate is considered sub-optimal for rubber cultivation. The prevalence of the powdery mildew disease (Oidium heveae) in this region has decreased the annual latex yield by 20%. Rubber latex yield is influenced by several factors, including temperature, disease, other biotic conditions, and plantation management. However, the interrelationships and potential influencing networks between rubber latex yield and these factors are rarely quantitatively assessed, and understanding their impacts on latex yield could inform better management practices. To address this gap, we investigated the effects of temperature, phenology, and powdery mildew disease on rubber latex yield in March using observational data on daily rubber latex yield combined with detailed phenology, powdery mildew, and temperature data from 2004 to 2010 in a state farm in the Xishuangbanna, Yunnan, China. We found that the critical influencing periods of daily temperature difference (or diurnal temperature difference) on the rubber latex yield were during Nov 27-Jan 19 and Jan 21-Mar 17. Partial least square regression analysis and variance partitioning analysis were conducted on the 35 phenological variables, eight powdery mildew-related variables, and two climatic variables. The most influential factors were identified as the factors of the daily temperature differences during Jan-Mar, the duration of leaf flushing phenology, and mean and maximum percentage of leaves infected by powdery mildew. Subsequent canonical correlation analysis and linear regression found that temperature difference directly affected the rubber latex yield and indirectly affected the yield through phenology and powdery mildew disease. Raised daily temperature differences from Jan to Mar had the greatest impact, leading to a higher rubber latex yield. Our comprehensive quantitative assessment revealed the relative importance of antecedent daily temperature differences, phenology, and powdery mildew disease as well as their complex interconnections in influencing rubber latex yield. Our findings are essential to future studies on both powdery mildew disease and rubber latex yield, and also develop rubber latex models

Rediscovery of Five <i>Rinodina</i> Species Originally Described from Southwest China and One New Species

Rinodina is a lichenized fungal genus belonging to the Physciaceae, with c. 300 species worldwide. Nearly a century ago, Zahlbruckner described five species of the genus Rinodina from Southwest China. The type collections were the only records for these species. In the present study, new records for four of these species: Rinodina cornutula, R. globulans, R. handelii, and R. setschwana, and a recently described species, R. pluriloculata, are documented based on specimens collected from the holotype localities. Furthermore, one new species was discovered: Rinodina hengduanensis, characterized by areolate to subsquamulose thallus, jigsaw-like areoles, lecanorine apothecium, and Dirinaria-type ascospores. Rinodina setschwana is transferred to the genus Buellia based on its morphology, chemistry, and phylogeny and proposed as Buellia setschwana. We provide detailed morphological descriptions, pictures, and molecular phylogenetic analyses

Taxonomy of Buellia epigaea-group (Caliciales, Caliciaceae), revealing a new species and two new records from China

During the Second Tibetan Plateau Scientific Expedition and Research Program, we discovered that white terricolous lichenized fungal species of Buellia De Not. were widely distributed across the Tibetan Plateau. After examining their morphology, chemistry and phylogeny, we describe Buellia alpina Xin Y. Wang & Li S. Wang, sp. nov. as new to science. It is present in alpine meadows, and is characterized by its effigurate thallus, distinct linear marginal lobes, cover of thick white pruina and four-spored asci. This is also the first report of Buellia elegans Poelt and Buellia epigaea (Pers.) Tuck from China. The Buellia epigaea-group has previously been characterized by white and often effigurate thalli that occur mainly on soil. However, our results show that species in this group actually belong to two distinct clades. This conclusion is based on analyses of the nuITS region and the combined regions dataset (nuITS-nuLSU-mtSSU-β-tubulin). We discuss differences in morphology, anatomy, chemistry and ecology among the putative Buellia epigaea-group. Detailed descriptions and figures for the three species from China and a key for species of Buellia epigaea-group are provided