Colletotrichum truncatum Causing Anthracnose of Tomato (Solanum lycopersicum L.) in Malaysia.

Tomato (Solanum lycopersicum L.) is a popular nutritious vegetable crop grown in Malaysia and other parts of the world. However, fungal diseases such as anthracnose pose significant threats to tomato production by reducing the fruit quality and food value of tomato, resulting in lower market prices of the crop globally. In the present study, the etiology of tomato anthracnose was investigated in commercial tomato farms in Sabah, Malaysia. A total of 22 fungal isolates were obtained from anthracnosed tomato fruits and identified as Colletotrichum species, using morphological characteristics. The phylogenetic relationships of multiple gene sequence alignments such as internal transcribed spacer (ITS), ß-tubulin (tub2), glyceraldehyde 3-phosphate dehydrogenase (gapdh), actin (act), and calmodulin (cal), were adopted to accurately identify the Colletotrichum species as C. truncatum. The results of pathogenicity tests revealed that all C. truncatum isolates caused anthracnose disease symptoms on inoculated tomato fruits. To our knowledge, the present study is the first report of tomato anthracnose caused by C. truncatum in Malaysia. The findings of this study will be helpful in disease monitoring, and the development of strategies for effective control of anthracnose on tomato fruits.

Genome-Wide Association Study Reveals Marker Trait Associations (MTA) for Waterlogging-Triggered Adventitious Roots and Aerenchyma Formation in Barley.

Waterlogging is an environmental stress, which severely affects barley growth and development. Limited availability of oxygen in the root zone negatively affects the metabolism of the whole plant. Adventitious roots (AR) and root cortical aerenchyma (RCA) formation are the most important adaptive traits that contribute to a plant's ability to survive in waterlogged soil conditions. This study used a genome-wide association (GWAS) approach using 18,132 single nucleotide polymorphisms (SNPs) in a panel of 697 barley genotypes to reveal marker trait associations (MTA) conferring the above adaptive traits. Experiments were conducted over two consecutive years in tanks filled with soil and then validated in field experiments. GWAS analysis was conducted using general linear models (GLM), mixed linear models (MLM), and fixed and random model circulating probability unification models (FarmCPU model), with the FarmCPU showing to be the best suited model. Six and five significant (approximately -log10 (p) ≥ 5.5) MTA were identified for AR and RCA formation under waterlogged conditions, respectively. The highest -log10 (p) MTA for adventitious root and aerenchyma formation were approximately 9 and 8 on chromosome 2H and 4H, respectively. The combination of different MTA showed to be more effective in forming RCA and producing more AR under waterlogging stress. Genes from major facilitator superfamily (MFS) transporter and leucine-rich repeat (LRR) families for AR formation, and ethylene responsive factor (ERF) family genes and potassium transporter family genes for RCA formation were the potential candidate genes involved under waterlogging conditions. Several genotypes, which performed consistently well under different conditions, can be used in breeding programs to develop waterlogging-tolerant varieties.

Genome-wide association study reveals a genomic region on 5AL for salinity tolerance in wheat.

Soil salinity is a major threat to crop productivity and quality worldwide. In order to reduce the negative effects of salinity stress, it is important to understand the genetic basis of salinity tolerance. Identifying new salinity tolerance QTL or genes is crucial for breeders to pyramid different tolerance mechanisms to improve crop adaptability to salinity. Being one of the major cereal crops, wheat is known as a salt-sensitive glycophyte and subject to substantial yield losses when grown in the presence of salt. In this study, both pot and tank experiments were conducted to investigate the genotypic variation present in 328 wheat varieties in their salinity tolerance at the vegetative stage. A Genome-Wide Association Studies (GWAS) were carried out to identify QTL conferring salinity tolerance through a mixed linear model. Six, five and eight significant marker-trait associations (MTAs) were identified from pot experiments, tank experiments and average damage scores, respectively. These markers are located on the wheat chromosomes 1B, 2B, 2D, 3A, 4B, and 5A. These tolerance alleles were additive in their effects and, when combined, increased tolerance to salinity. Candidate genes identified in these QTL regions encoded a diverse class of proteins involved in salinity tolerance in plants. A Na+/H+ exchanger and a potassium transporter on chromosome 5A (IWB30519) will be of a potential value for improvement of salt tolerance of wheat cultivars using marker assisted selection programs. Some useful genotypes, which showed consistent tolerance in different trials, can also be effectively used in breeding programs.

Estimation of Yield, Photosynthetic Rate, Biochemical, and Nutritional Content of Red Leaf Lettuce (Lactuca sativa L.) Grown in Organic Substrates.

This study aimed to evaluate the effect of organic substrates on the growth yield, photosynthetic response, and nutritional profile of red leaf lettuce grown in different compositions of cocopeat (CP), sawdust (SD), and rice husk (RH). The result showed that the properties of substrates were influenced variably by their mixing ratios. The highest water holding capacity and moisture content were found in CP, and it provided the preferable pH, electrical conductivity, bulk density, and air-filled porosity in association with other categories of the substrate. Cocopeat-based media provides ample microclimate conditions in the root region of plants and increased their height, number of leaves, and fresh biomass components. The utmost dry biomass of plant parts also remarkably increased in CP; L*, a*, and b* chromaticity of leaves remained unchanged. The maximum chlorophyll content was attained in CP substrate, except for chlorophyll a/b, which was higher in RH. The net photosynthetic rate (PN), transpiration rate (E), and nitrate in leaves were enhanced substantially in CP, while it was lower in SD. Biochemical compositions and nutrients in leaves were likewise stimulated under the culture of cocopeat-based media. Results indicate that cocopeat, sawdust, and rice husk are a possible substrates mixture in a volume ratio of 3:1:1, which would be a better choice in the cultivation of red leaf lettuce.

Improving Performance of Salt-Grown Crops by Exogenous Application of Plant Growth Regulators.

Soil salinity is one of the major abiotic stresses restricting plant growth and development. Application of plant growth regulators (PGRs) is a possible practical means for minimizing salinity-induced yield losses, and can be used in addition to or as an alternative to crop breeding for enhancing salinity tolerance. The PGRs auxin, cytokinin, nitric oxide, brassinosteroid, gibberellin, salicylic acid, abscisic acid, jasmonate, and ethylene have been advocated for practical use to improve crop performance and yield under saline conditions. This review summarizes the current knowledge of the effectiveness of various PGRs in ameliorating the detrimental effects of salinity on plant growth and development, and elucidates the physiological and genetic mechanisms underlying this process by linking PGRs with their downstream targets and signal transduction pathways. It is shown that, while each of these PGRs possesses an ability to alter plant ionic and redox homeostasis, the complexity of interactions between various PGRs and their involvement in numerous signaling pathways makes it difficult to establish an unequivocal causal link between PGRs and their downstream effectors mediating plants' adaptation to salinity. The beneficial effects of PGRs are also strongly dependent on genotype, the timing of application, and the concentration used. The action spectrum of PGRs is also strongly dependent on salinity levels. Taken together, this results in a rather narrow "window" in which the beneficial effects of PGR are observed, hence limiting their practical application (especially under field conditions). It is concluded that, in the light of the above complexity, and also in the context of the cost-benefit analysis, crop breeding for salinity tolerance remains a more reliable avenue for minimizing the impact of salinity on plant growth and yield. Further progress in the field requires more studies on the underlying cell-based mechanisms of interaction between PGRs and membrane transporters mediating plant ion homeostasis.

Which factor contribute most to empower farmers through e-Agriculture in Bangladesh?

The purpose of this research was designed to investigate the impact of e-Agriculture on farmers of Bangladesh. Empowerment is stratified as economic, family and social, political, knowledge and psychological empowerment. Data were collected in Bhatbour Block of Dhighi union under Sadar Upazila of Minikganj District. Data were collected in two phases from the same group of respondents (in August, 2013 and September, 2015). Two sample t test and step-wise multiple regression method were used for analysis. The results showed that e-Agriculture had significant impact on the empowerment of farmers of Bangladesh. Additionally, the study concluded that the most significant factor behind the empowerment of farmer was the use of e-Agriculture which could explain almost 84 % of the total variation of the empowerment. Based on the findings, it is recommended that government should implement e-Agriculture based projects on a massive scale for the empowerment of the farmers.