Plant-associated microbes represent a key determinant of plant fitness through acquiring nutrients, promoting growth, and resisting to abiotic and biotic stresses.  However, an extensive characterization of the bacterial and fungal microbiomes present in different plant compartments of soybean in field conditions has remained elusive.  In this study, we investigated the effects of four niches (roots, stems, leaves, and pods), four genotypes (Andou 203, Hedou 12, Sanning 16, and Zhonghuang 13), and three field locations (Jining, Suzhou, and Xuzhou) on the diversity and composition of bacterial and fungal communities in soybean using 16S and internal transcribed spacer rRNA amplicon sequencing, respectively.  The soybean microbiome significantly differed across organs.  Host genotypes explained more variation in stem bacterial community composition and leaf fungal community composition.  Field location significantly affected the composition of bacterial communities in all compartments and the effects were stronger in the root and stem than in the leaf and pod, whereas field location explained more variation in stem and leaf fungal community composition than in the root and pod.  The relative abundances of potential soybean fungal pathogens also differed among host organs and genotypes, reflecting the niches of these microbes in the host and probably their compatibility to the host genotypes.  Systematic profiling of the microbiome composition and diversity will aid the development of plant protection technologies to benefit soybean health.  

Elevating soil water content (SWC) through irrigation was one of the simple mitigation measures to improve crop resilience to heat stress.  The response of leaf function, such as photosynthetic capacity based on chlorophyll fluorescence during the mitigation, has received limited attention, especially in field conditions.  A two-year field experiment with three treatments (control treatment (CK), high-temperature treatment (H), and high-temperature together with elevating SWC treatment (HW)) was carried out during grain filling with two maize hybrids at a typical station in North China Plain.  Averagely, the net photosynthetic rate (P_n) was improved by 20%, and the canopy temperature decreased by 1–3°C in HW compared with in H in both years.  Furthermore, the higher SWC in HW significantly improved the actual photosynthetic rate (Phi2), linear electron flow (LEF), variable fluorescence (F_v), and the maximal potential quantum efficiency (F_v/F_m) for both hybrids.  Meanwhile, different responses in chlorophyll fluorescence between hybrids were also observed.  The higher SWC in HW significantly improved thylakoid proton conductivity (gH⁺) and the maximal fluorescence (F_m) for the hybrid ZD958.  For the hybrid XY335, the proton conductivity of chloroplast ATP synthase (vH⁺) and the minimal fluorescence (F_o) was increased by the SWC.  The structural equation model (SEM) further showed that SWC had significantly positive relationships with P_n, LEF, and F_v/F_m.  The elevating SWC alleviated heat stress with the delayed leaf senescence to prolong the effective period of photosynthesis and enhanced leaf photosynthetic capacity by improving Phi2, LEF, F_v, and F_v/F_m.  This research demonstrates that elevating SWC through enhancing leaf photosynthesis during grain filling would be an important mitigation strategy for adapting to the warming climate in maize production.

The present study reports the sublethal effects of the entomopathogenic fungus, Aschersonia aleyrodis (Webber) on Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae).  A fungal suspension of A. aleyrodis isolate Aa005 containing 1×10⁷ conidia mL^–1 was sprayed against B. tabaci on eggplant leaves under greenhouse conditions.  The effects of fungal application on survival as well as life table parameters of the whitefly were observed at different post inoculation periods.  The results indicated that A. aleyrodis can significantly affect the survival of 1st, 2nd, and 3rd nymphal instars of B. tabaci.  Developmental periods of different instar nymphs were not affected by fungal application.  A. aleyrodis spores persisted well and significantly affected the survivorship of young instar nymphs of B. tabaci at different post incubation periods.  Life table results suggested that A. aleyrodis has no impact on general fecundity and longevity of B. tabaci.  When the pathogen was exposed to the open environment and maintained for a relatively longer period, a reduction in the reproductive rate and intrinsic rate of increase was caused by the fungal spores, though the sublethal effects were not as good as the control treatment.  The results suggest that the ability of spores to suppress an increase in whitefly population persists well after incubation of spores to the external environment (up to 9 days).  

Gossypium hirsutum races are believed to be potential reservoirs of desirable traits, which can play crucial roles to overcome the existing narrow genetic base of modern Upland cotton cultivars.  However, prior to utilizing the races in cotton improvement programs, understanding their genetic constitutions is needed.  Thus, this study used molecular and morphological techniques to characterize 110 G. hirsutum germplasm including 109 semi-wild accessions and one Upland cotton cultivar, CRI12.  In the study, 104 SSR markers detected 795 alleles, with an average of 7.64 alleles per marker, ranging from 3 to 14, and average polymorphism information content (PIC) value of 0.71.  And 96 of the markers were found to be highly informative, with PIC value≥0.50.  Pairwise genetic similarity coefficient across the accessions ranged from 0.19 to 1.00, with an average value of 0.46.  Morphological characterization was done using fiber length, fiber strength, micronaire, fiber uniformity index, and fiber elongation.  Pairwise taxonomic distance within the accessions ranged from 0.17 to 3.41, with a mean of 1.33.  The SSR and fiber quality traits data set based unweighted pair group method of arithmetic mean (UPGMA) analysis grouped the accessions into 7 and 12 distinct clusters, respectively, that corresponds well with the results of principal component analysis (PCA).  Our study revealed the existence of vast molecular and morphological diversities within the accessions and provided valuable information on each semi-wild accession for quick and better informed germplasm utilization in cotton breeding programs.