Identification, pathogenicity, and fungicide sensitivity of Eutiarosporella dactylidis associated with leaf blight on maize in China

Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.

Assessment of biological changes in wheat seedlings induced by ^(12)C^(6+)-ion irradiation

The present study was designed to evaluate the effect of 12 6+ C ion beam (10～80 Gy) on biological changes of wheat seedlings. Reactive oxygen species (ROS)-related biomarkers and the quantification of plant survival and growth were examined at 10 day after carbon ions irradiation (LET: 30.8 keV/μm). The results showed that heavy ions obviously enhanced ROSs reflected by the production of O2 and H2O2 as well as TBARS, and - treatment with 20 Gy achieved the peak value, suggesting that higher mutagenic potential may occur at 20 Gy. Simultaneously, increase of SOD activity was induced by heavy ions to counteract ROS accumulation. On the other hand, higher doses at 40 and 80 Gy inhibited wheat growth and survival in comparison with the control, and reversely lower doses at 10 or 20 Gy stimulated wheat growth and survival. In conclusion, the above observations imply that a dose range of 20~40 Gy is likely promised for wheat mutation breeding.

Effects of Artificial Aging on Physiological Characteristics and Seed Vigor of Medicago ruthenica Seeds

As shown by the changes in physiological characteristics and seed vigor of three Medicago ruthenica samples during artificial aging process, the germination potential, germination rate, germination index, vigor index and simple vigor index declined with the extension of aging time on the whole. After artificial aging for 6 min, the vigor was higher than that of the control. The conductivity, malondialdehyde content and soluble polysaccharide content of seed leachate increased with the aging time and negatively correlated （ P 〈 0.05） with the seed vigor indicators. The physiological indicators were very significantly correlated （P 〈 0.01 ） with the vigor indicators in the Medicago ruthenica sample from Dorbod Qi, UIanqab City（China）.

Ecological Environment Conservation and Restoration and Sustainable Development of Minqin Oasis

Minqin oasis in the lower reaches of the Shiyang River is a main natural barrier for the Wuwei Basin. Due to the combined influence of human activities and natural factors in the past half a century, water quality in the lower reaches of the Shiyang River decreased and ecological environment deteriorated, which influenced sustainable development of this area and surrounding area seriously. This paper analyzed current situation and reasons of the deteriorated ecological environment in the lower reaches of the Shiyang River, and proposed that water environment regulation was the primary task in the eco-environment control of Minqin area, specifically,(a) By using existing policies, accelerating the construction of water-saving agriculture in the middle reaches of the Shiyang River, water quantity in the lower reaches would be guanranted, water shortage for agricultural production and ecological use in Minqin oasis would be relieved;(b) Unreasonable human activities such as overexploitation of underground water should be controlled strictly;(c) Water conservancy project should be developed vigorously to ensure rate of flow. It was expected that the above schemes would contribute to the benign circulation of ecological environment in Minqin oasis.

Acetic acid mitigated salt stress by alleviating ionic and oxidative damages and regulating hormone metabolism in perennial ryegrass (Lolium perenne L.)

Organic chemical priming is an effective strategy in mitigating salt stress to plants.The objective of this study was to determine effects and associated mechanisms of acetic acid regulating plant tolerance to salt stress.Perennial ryegrass plants were pre-treated with 20 mM acetic acid and subsequently subjected to salt stress for 28 days.Salt stress caused increased endogenous acetic acid content with up-regulated expression of its key biosynthetic gene LpPDC1.Application of acetic acid effectively alleviated salt caused damage in perennial ryegrass.Acetic acid treatment increased K^(+) content and suppressed Na^(+) accumulation to maintain a higher K^(+)/Na^(+) ratio in leaves exposed to salt stress.Plants O_(2)^(−) treated with acetic acid also had significantly lower levels of and H_(2)O_(2),but higher SOD and CAT activities than those of the control after 21 days of salt stress.Acetic acid treatment also altered the plants endogenous phytohormone content with higher content of jasmonate(including JA,JA-ILe,and cis-OPDA),auxin(IAA),and cytokinins(CK,such as tZ,cZR,and iP),but lower content of abscisic acid(ABA)under salt stress conditions.Furthermore,expression of genes involved in JA,IAA,and CK biosynthesis and signaling pathways were up-regulated,while those involved in ABA were down-regulated by acetic acid treatment under salt stress.The results demonstrate that acetic acid could mitigate salt stress in perennial ryegrass by regulating K^(+) and Na^(+) balance,promoting ROS scavenging,and activating stress-protection hormone synthesis and signaling.

Research Progress of Soil Microbiology

This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass nitrogen and microbial biomass phosphorus,function of microbial and screening and application of beneficial microorganisms etc.,and future research are discussed combined with our project team for many years of work.

Effects of Modulation Methods on the Drying Characteristics and Nutritional Quality of Medicago sativa Hay

Two-year-old Medicago sativa at budding initial stage was taken as research materials.Five methods were used to make green hay,including flatting stems ＋ spraying 2.5% K2CO3,flatting stems,sun curing,drying in shade and drying under 105 ℃ condition（CK）.Besides,effects of different green hay making methods on dry characteristics and nutritional quality of M.sativa green hay were studied,and a comprehensive evaluation of M.sativa green hays was conducted.Results showed that,except CK,the drying rates in other making methods were all fast at first,and then slow down.Both of drying under 105 ℃ condition and flatting stems ＋ spraying K2CO3 could speed up drying rate and reduce nutritional losses of green hay.Sun curing could also speed up drying rate,but it could not maintain the quality of green hay.The results of Grey Relational Analysis on five green hay making methods indicated that CK had the best comprehensive performance,followed by green hays made by flatting stems ＋ spraying K2CO3.Therefore,flatting stems ＋ spraying K2CO3 was a quick and easy method to make green hay,and it was worth to be recommended in practical production.