Reproduction response of Colletotrichum fungi under the fungicide stress reveals new aspects of chemical control of fungal diseases.

Systemic fungicides and antifungals are used as frontline treatments for fungal diseases in plants and humans. It is generally accepted that fungicides will bring significant negative side-effects to the environment and result in fungicide resistance in the pathogenic fungi. Although previous research has focused on fungicide application rates and fungal resistance for a long time, little attention has been paid to fungicide residues after treatment, especially their potential role in fungal growth and sporulation. Here we investigated the effect of fungicides at sublethal concentrations on fungal sporulation. The results showed that two kinds of 14α-demethylase inhibitors (DMIs) fungicides increased the number of isolates of Colletotrichum spp. to sporulate on PDA. Both on PDA medium and plant tissue, low concentration of DMI fungicides could promote spore production of Colletotrichum spp., whereas pyraclostrobin, a quinone outside inhibitor (QoIs), had no significant effects on sporulation of Colletotrichum spp. Transcriptomic analysis suggested that the DMIs fungicide stress signal may be transmitted to the central regulatory pathway through the FluG-mediated signalling pathway, and further confirmed the morphological effect of DMI fungicide on promoting sporulation of Colletotrichum. To our knowledge, this is the first study to provide insights into the reproductive response of fungi in response to fungicide stress. Our findings indicate that fungicides have two-way effects on the growth and reproduction of pathogenic fungi and provide a new basis for the scientific and rational use of fungicides.

Biological characteristics of wild Angelica sinensis seed / 中国中药杂志

Wild Angelica sinensis is almost endangered, studying the biological characteristics of wild A. sinensis seeds is helpful for varietal improvement and its conservation. This paper systematically studied the morphological structure, thousand seed weight, viability, storage and other basic biological characteristics of wild A. sinensis fruits and seeds, and focused on the germination of excised embryos,the development of embryo, the effects of the temperature,light and hormones on seed germination.The study found that:①The embryos are not fully developed when harvested, the initial germination rate was low, the embryos can develop. After 15 days of low temperature storage, the embryos can develop completely and the germination rate is significantly increased. These results show that wild A. sinensis seeds have no dormancy, and the low germination rate is due to the low maturity of wild A. sinensis seeds. ②The sui-table germination temperature of wild A. sinensis is 15-25 ℃,and the optimal temperature is 20 ℃. Light does not affect the germination of A. sinensis seeds.③The applicable concentration of GA_3 can promote seeds germination, IAA and 6-BA has no significant effect on germination.④The optimum storage condition is dry storage at 4 ℃. Wild A. sinensis seeds can be stored for 1.5 years and cultivated seeds can be stored for 1 year.During the introduction and conservation, the best treatment conditions were dry storage at 4 ℃ for 30 d and soaking seeds with 200 mg·L~(-1) GA_3, the germination rate can reach 86.7%.

Population characteristics and threatened of wild Angelica sinensis in Gansu province / 中国中药杂志

The study aims to investigate spatial distribution pattern and age structure of wild Angelica sinensis in Gansu province.Ten plots each with an area of 100 m2 were set and the spatial coordinates of all wild A. sinensis individuals were measured within each plot. Based on plant individual mapping data,we explored the spatial distribution pattern and its differences between different life history stages of wild A. sinensis in Gansu province by using nearest neighbor distance statistics. Correlation analysis were carried out to explore the relationship between spatial aggregation degree and topographic factors. We also distinguished individuals to three life history stages( i.e. seedlings,adults and boltings) and then test the differences among/between them using nonparametric test.(1)We found that the dominant spatial distribution pattern of wild A. sinensis population in Gansu was aggregated distribution. There was no significant correlation between spatial aggregation degree of wild A. sinensis and altitude,slope and aspect. There was no significant difference between the average distance from seedlings to their nearest bolting individuals; the average distance from adult individuals to their nearest seedlings was significantly larger than the average distance from adult individuals to their nearest adult individuals; and the average distance from bolting individuals to their nearest adult individuals was significantly smaller than the average distance from bolting individuals to their nearest bolting individuals.(2)The age structure was showed as a declining population,characterized by less seedlings and bolting individuals,while more adult individuals within population. The population characteristics of wild A. sinensis,characterized by aggregated distribution pattern and senescent type of age structure,are disadvantage to its population development. The factors,such as habitat specialization,human activities and intraspecific competition,which shapes the current population characteristics,may increase the threatened status of wild A. sinensis. We suggest to strengthen the protection of wild A. sinensis.

Relationship between seedling grade of angelica and biomass accumulation and quality of product / 中国中药杂志

<p><b>OBJECTIVE</b>To research the relationship between the seedling grade of angelica and the biomass accumulation, output and quality of product, so as to provide base for establishing seedling standard.</p><p><b>METHOD</b>Thirty seedlings of Angelica were collected from the main production area in Gansu province, such as Minxian, Zahngxian, Dangchang and Weiyuan county, all the samples were measured with weigh of single seedling and the seedling were divided into three grade by the clustering analysis results, the grade were made to treatment to do field test and laboratory experiment.</p><p><b>RESULT</b>The weigh of dry root, above ground and the whole plant in growth period of treatment 2 (the weigh of single seedling between 0.74-1.38 g) were all superior to other treatments and the ck. The treatment 2 had low bolting percentage, the weigh of single root was higher and the yield was the highest. The characters of product from the treatment 2 was well and the content of ferulic acid was higher than the standard of Chinese pharmacopoeia (2010 year part 1).</p><p><b>CONCLUSION</b>The plant from the grade 2 seedling with larger growth increment, higher output and better quality, which can be the best seedling in production.</p>

[Effects of exogenous ABA and GA3 on sugar concentration in flesh of cara cara navel orange].

The concentration of glucose, fructose, sucrose and total sugar were determined after exogenous ABA and GA3 treatment during young period of fruit and before fruit coloring in flesh of Cara Cara Navel Orange. The results showed that 10 mg x L(-1) ABA treatment improved glucose, fructose and total sugar concentration significantly or very significantly, 50 mg x L(-1) ABA treatment improved sucrose concentration very significantly, but 100 mg x L(-1) ABA treatment reduced glucose concentration very significantly. GA3 treatment of lower and middle concentrations (10, 50 and 250 mg x L(-1)) improved sucrose concentration very significantly, 10 mg x L(-1) GA3 treatment had no remarkable effect on glucose and fructose concentration but improved total sugar concentration very significantly, GA3 treatment of 50, 250 and 500 mg x L(-1) decreased glucose, fructose and total sugar concentration very significantly. Therefore, ABA treatment of lower concentration could improve one or several kinds of sugar concentration, but GA3 treatment of higher concentration (250 and 500 mg x L(-1)) prohibited sugar accumulation in flesh of Cara Cara Navel Orange seriously.