Genome sequence data of Leptosphaerulina arachidicola, a causal agent of peanut scorch spot in China

Peanut scorch spot caused by Leptosphaerulina arachidicola is one of the most severe leaf diseases of peanut that causes significant yield loss. Here, we report the first high quality genome sequence of L. arachidicola JB313 isolated from an infected peanut leaf in China. The genome size is 47.66 Mb, consisting of 65 scaffolds (N50 length = 1.58 Mb) with a G+C content of 49.05%. The information in this report will provide a reference genome for future studies on peanut scorch spot pathogen in peanut.

Morpho-molecular Identification and Chemical control of Alternaria alternata,causing leaf blight of Gardenia jasminoides Eills in China

Gardenia jasminoides Eills is a traditional aromatic and medicinal plant that is widely cultivated in China. In 2020, a severe leaf disease on Gardenia was observed in a growing herbal medicine area in Jian County, of Jiangxi Province, China. The causal agent was identified as Alternaria alternata (Fr.) Keissler. by amplification and sequencing the internal transcribed spacer (ITS) region, followed by phylogenetic analysis. Koch's postulates were confirmed by a pathogenicity test conducted with healthy gardenia, including reisolation and identification. To our knowledge, this is the first report of leaf blight caused by Alternaria alternata on Gardenia jasminoides Eills in JiangXi, China. PDA plate bacteriostatic experiment results showed that: Hexaconazole had the best inhibiting effect, which the EC 50 was 14.45 ppm. Therefore, the results are preliminary but promising for future field applications.

Virus-Induced Gene Silencing of SlWRKY79 Attenuates Salt Tolerance in Tomato Plants

Previous studies have shown that WRKY transcription factors play important roles in abiotic stress responses. Thus, virus-induced gene silencing (VIGS) was used to identify the function of SlWRKY79 in the salt tolerance of tomato plants by downregulating the expression of the SlWRKY79 gene. Under the same salt treatment conditions, the SlWRKY79-silenced plants showed faster stem wilting and more severe leaf shrinkage than the control plants, and the bending degree of the stem of the SlWRKY79-silenced plants was also greater than that of the control plants. Physiological analyses showed that considerably higher levels of hydrogen peroxide (H2O2), superoxide anion (O2−), and abscisic acid (ABA) accumulated in the leaves of the SlWRKY79-silenced plants than in those of the controls after salt treatment. Taken together, our results suggested that SlWRKY79 plays a positive regulatory role in salt tolerance in tomato plants.

Characterization of two Cucumber mosaic virus isolates infecting Allium cepa in Turkey

Cucumber mosaic virus (CMV) is polyphagous, infecting plants in several families. CMV has occurred as a minor pathogen in Allium crops in several Mediterranean countries, but little was known of the virus naturally infecting Allium spp. This study completed molecular and biological characterization of CMV-14.3Po and CMV-15.5Po, two newly identified CMV isolates infecting onion (Allium cepa L.) in Turkey. Phylogenetic, and nucleotide and amino acid sequence identity analyses of partial RNA2 and RNA3 of the two isolates showed that they were very similar to other CMV isolates from Mediterranean, European, and East Asian countries. Phylogenetic analysis of the partial sequence of RNA3 also showed that the onion isolates belong to subgroup IA. Onion isolates were mechanically transmissible, and caused mild leaf malformation on onion, severe leaf malformation and stunting on garlic (Allium sativus L.), and mosaic and mottle on cucumber (Cucumis sativus L.) and melon (Cucumis melo L.).

IMA Genome - F13

ABSTRACT Draft genomes of the fungal species Ambrosiella cleistominuta, Cercospora brassicicola, C. citrullina, Physcia stellaris, and Teratosphaeria pseudoeucalypti are presented. Physcia stellaris is an important lichen forming fungus and Ambrosiella cleistominuta is an ambrosia beetle symbiont. Cercospora brassicicola and C. citrullina are agriculturally relevant plant pathogens that cause leaf-spots in brassicaceous vegetables and cucurbits respectively. Teratosphaeria pseudoeucalypti causes severe leaf blight and defoliation of Eucalyptus trees. These genomes provide a valuable resource for understanding the molecular processes in these economically important fungi.

Effect of Salinity and Nitrogen Sources on the Leaf Quality, Biomass, and Metabolic Responses of Two Ecotypes of Portulaca oleracea

Halophytic plants are, by definition, well adapted to saline soils. However, even halophytes can face nutritional imbalance and the accumulation of high levels of compounds such as oxalic acid (OA), and nitrate (NO3−). These compounds compromise the potential nutritional health benefits associated with salt-tolerant plants such as Portulaca oleracea or Purslane. Purslane has long been known to be a highly nutritious leafy vegetable particularly with respect to high levels of omega-3 fatty acids. Thus, preventing the accumulation of non-nutritional compounds will allow plants to be grown in saline conditions as crops. Two ecotypes (ET and RN) of Portulaca oleracea plants were grown under growth room conditions with two levels of salinity (0, 50 mM NaCl) and three ratios of nitrate: ammonium (0:100%; 33:66%; 25:75% NO3−:NH4+). The results show that both ecotypes, when exposed to elevated NO3−, showed severe leaf chlorosis, high levels of OA, citric acid, and malic acid. Compared to ecotype RN, ecotype ET, exposed to elevated NH4+ concentrations (33% and 75%) and 50 mM NaCl, displayed a marked reduction in OA content, increased total chlorophyll and carotenoid contents, crude protein content, total fatty acid (TFA) and α-Linolenic acid (ALA), enhancing leaf quality. This opens the potential to grow high biomass, low OA P. oleracae crops. Lastly, our experiments suggest that ecotype ET copes with saline conditions and elevated NH4+ through shifts in leaf metabolites.

Effect of Salinity and Nitrogen Sources on Leaf Quality, Biomass, and Metabolic Responses of Two Ecotypes of Portulaca oleracea

Halophytic plants are, by definition, well adapted to saline soils. However, even halophytes can face nutritional imbalance and accumulation of high levels of compounds such as oxalic acid (OA), and nitrate (NO3¯). These compounds compromise the potential nutritional health benefits associated with salt tolerant plants such as Portulaca oleracea. Thus, preventing the accumulation of non-nutritional compounds will allow plants to be grown in saline conditions as crops. To this end, two ecotypes (ET and RN) of Portulaca oleracea plants were grown under growth room conditions with two levels of salinity (0, 50 mM NaCl) and three ratios of nitrate: ammonium (0:100%; 33:66%; 25:75% NO3¯:NH4+). The results showed that both ecotypes exposed to elevated NO3¯, showed severe leaf chlorosis, high levels of OA, citric acid, and malic acid, while plants of ecotype ET exposed to elevated NH4+ concentrations (33% and 75%) and 50 mM NaCl displayed a marked reduction in OA content, increased total chlorophyll and carotenoid contents, crude protein content, total fatty acid (TFA) and α-Linolenic acid (ALA) thus enhancing leaf quality. This opens the potential to grow high biomass, low OA P. oleracae crops. Lastly, our experiments suggest that ecotype ET copes with saline conditions and elevated NH4+ through shifts in leaf metabolites.

Two New severe leaf spot diseases on forest trees of Seoni Forest (MP)

During the survey of the forest fungal disease, of Seoni district,(M.P), two severe leaf spot diseases on Chroloxylonswietinia and of Adina cordifoliaRox were observed in Seoni, forest Seoni(M.P) during July to September.2017- 18. The casual organism was identified as Psuedocercosporachloroxyliae and MycovellosiellaadinaeFirdousi respectively which were identified with the help of literature and confirmed by the experts. This is first report from Seoni and Madhya Pradesh.