Cereal Research Communications最新文献

Chuanmai104 (CM104), an elite wheat (Triticum aestivum L.) variety that currently produces the highest yield per unit area in southwestern China, plays a critical role in wheat production. The high quality and stability of grain traits are important factors that ensure the high, stable yields of CM104 in different production areas. In this study, six grain traits of CM104 sampled from 19 environments in five provinces of China during 2018–2022 were evaluated. The traits comprised thousand-kernel weight, grain length, grain width, grain length–width ratio, grain circumference, and grain surface area. Fifteen quantitative trait loci (QTLs) associated with the grain traits were identified based on a recombinant inbred lines (F_9–10) population derived from the cross between CM104 and the landrace Baimaomai (BMM), nine and six QTLs derived from CM104 and BMM, respectively. Three mainly pleiotropic QTLs derived from CM104, namely QTL10 (grain circumference, grain surface area), QTL11 (grain length, grain circumference), and QTL12 (grain length, grain circumference), were expressed significantly and stably in multiple environments, and explained 3.34–5.06%, 5.32–6.50%, and 6.00–12.13% of the phenotypic variation, respectively. The pyramiding of multiple genes is hypothesized to have contributed to the stability of the CM104 grain traits in different environments. The results provide a basis for future improvement of yield and its stability in wheat.

This review meticulously explores the diverse methodologies and applications of chlorophyll fluorescence (CF) analysis, emphasizing its crucial role in field measurements, crop phenotyping, and monitoring within agricultural research. It is a useful tool in agricultural research since it helps researchers improve plant selection procedures and optimize crop production. The review clarifies the importance of CF in understanding energy transfer within the photosynthetic apparatus and related processes, highlighting its usefulness in evaluating the effects of abiotic stresses on photosynthetic performance. A highlight of this study is the critical investigation of CF imaging as a non-destructive phenotyping method. This technique not only quantifies photosynthetic tolerance mechanisms to various stimuli but also forecasts chloroplast activity and responses under diverse growth conditions, be they optimal or unfavorable. Focusing particularly on maize, this review evaluates the sensitivity of the photosynthetic apparatus to a spectrum of abiotic stressors. It offers invaluable insights into the nuanced responses of maize to these stressors, providing essential knowledge pertinent to climate change and the pursuit of sustainable farming practices. Moreover, it highlights the critical role of CF in assessing maize varieties under various stresses, viz., drought, heat, cold, nutrient deficiencies, disease resistance, and susceptibility. Comparative analysis of different maize varieties and the evaluation of hybrid performance through CF are also considerably covered. By delving into techniques, applications, and practical considerations, this review contributes significantly to the scholarly discourse on CF analysis in contemporary agriculture, offering a comprehensive understanding of its techniques and pragmatic implications.

The effect of potassium supply and plant density on maize (Zea mays L.) was investigated in terms of the leaf weight in the flowering stage, grain yield components, grain and stalk yield and their potassium, calcium and magnesium contents, in a field trial set up in Nagyhörcsök, Hungary, on a calcareous chernozem soil with poor to moderate potassium supplies. Different potassium supply levels were achieved by the initial build-up application of 0-240-480-960-1440 kg K₂O ha⁻¹ in autumn 1989. Adequate nitrogen and phosphorus supplies were provided by yearly NP fertilization. The year studied was favourable for maize growth and development. The maize hybrid Pioneer SC 3732 (FAO 450) was sown at plant densities of 24-48-72-96 thousand plants ha⁻¹. The plant density had a more pronounced effect on grain yield than the different K supplies. Stalk yields showed trends similar to those for grain yields, but plant density had the opposite effect on the leaf weight (g 20 leaves⁻¹) in the flowering stage. K fertilization increased the K content to the greatest extent in the vegetative parts (leaf and stalk), while increasing plant density had a reverse effect. The K-Ca-Mg antagonism was also the most pronounced in the vegetative parts, i.e. maize leaves in the flowering stage. According to the results obtained in the field trial, it seems that a century ago, in our grandparents’ time, food contained more minerals than nowadays, due to the fact that plant density decreases grain mineral composition more than mineral fertilization can increase it.

Wheat biofortification represents a promising avenue to combat global micronutrient deficiencies. Therefore, understanding the genetic basis of desirable alleles underpinning all minerals is important for wheat biofortification. A core collection of 111 wheat genotypes was evaluated for both years to measure macronutrient contents, including magnesium (Mg), calcium (Ca), phosphorus (P), and potassium (K). Our study showed significant natural phenotypic variation for all of the studied macronutrients underlying both years with high heritability values. Using a genome-wide association scan (GWAS), 474 significant SNP markers were detected and associated with all the evaluated macronutrients for both years. Upon GWAS analysis, several reliable genomic regions with different potential candidate genes were found to play essential roles in the biofortified wheat grains. For instance, the gene TraesCS1A02G261200 was located on chromosome 1A and annotated as calcium ion binding proteins. These proteins play a crucial role in regulating mineral accumulation in wheat grains by influencing signal transduction, mineral transporter regulation, stress responses, cell wall stability, seed development, and enzymatic activity modulation. Notably, the accessions carrying T allele showed a higher accumulation of Mg, P, and Ca in wheat grains than the accessions carrying C allele, suggesting the positive selection of the accessions carrying T allele in the wheat panel. Therefore, exploring the mechanisms and regulation of these proteins could lead to techniques for enhancing the nutritional value of wheat grains, specifically mineral content.

The experiment was conducted on the survival of Exserohilum rostratum through different sources i.e. soil, plant debris, and seed and also observed the infection percentage from wheat flower to seed. It was found that the survival of E. rostratum frequency varied in soil from (0.00–29.29%), plant debris (0.97–27.17%) and seed (3.26–24.80%). The maximum temperature, relative humidity (RH, morning), and rainfall were negatively correlated, while the minimum temperature and relative humidity (RH, evening) were positively correlated with the survival of the pathogen. The dissemination infection percentage on the palea in WAMI1 of (63.33%) was higher, followed by Lemma in WAMI 10 (40.74%) and the least transmission in Glume of (29.63%) in both WAMI-8 and WAMI-9, respectively. The seedling infection on susceptible variety showed black spots with blighted appearance lesions on primary leaf and histopathological test conducted on post-anthesis stage. The purpose of the investigation is to understand the survival of the pathogen in the absence of host and floral infection biology. Furthermore, this information is useful for integrated disease control measures in the future.

Banded leaf and sheath blight (BLSB) caused by necrotic fungus Rhizoctonia solani f. sp. sasakii is one of the major disease of maize. BLSB is reported globally and cause complete failure of maize crop depending upon the environmental conditions. R. solani has wide, diverse host range and ability to remain dormant under unfavourable conditions in sclerotial forms making the pathogen rather difficult to manage. Due to absence of a desired level of resistance in commercially popular varieties/ hybrids of maize, management through chemical control has been the most adopted method. Limitations of high costs, health hazards and environmental pollutions pose a serious threat by chemical control measures. In this review, we provide an updated comprehensive description of history, economic impact, distribution, symptoms and various control measures including cultural, host plant resistance, biological and need-based applications of chemicals. Recent studies revealed efficacy of stripping of lower two/three leaves at 40 days after sowing as an efficient cultural practice for managing this disease. However, for effective management of BLSB disease, there is an urgent need to integrate all the available control methods to achieve its sustainable management in future with minimized economical losses.

Indigenous landraces are heterogeneous and exhibit greater gene diversity, and are therefore an excellent source of variation and material for crop improvement. However, they are very prone to genetic erosion, therefore exploration of genetic variability in landraces is essential step for crop breeding. Discovery of the genetics of a character in rice, that cope adverse condition, is important for maintaining world-food supply. In this study, fifty rice genotypes were assessed for the phenotypic and genetic diversity and their relatedness using morpho-physiological traits of the genotypes. Further clustering and population structure analysis were performed using phenotypic and simple sequence repeat (SSR) markers data through unweighted pair group method with arithmetic mean (UPGMA) and STRUCTURE analysis. Significant variation among yield components were identified. Phenotypic and genotypic coefficients of variability were higher for filled grains, whereas heritability was highest for plant height. Panicle number and 100-grain weight displayed significant relationship with yield. Phylogenetic clustering of the agromorphological traits divided the genotypes into eight clusters, whereas SSR markers yielded ten clusters. SSR markers produced a total of 138 alleles varying from two to nine with 77.53% polymorphic allele having 3.69 alleles per locus (average). The polymorphic information content indices and observed number of alleles varied among markers with an average of 0.649, exhibiting RM336, RM316, and RM287 have the greatest potentiality in exploring genetic diversity among genotypes. Among the genotypes, Dolkochu, Jolduba, BRRI Dhan-32, and Mokbul displayed significant variability, suggesting their suitability as potential parents in hybridization programs. Population structure study demonstrated that the genotypes were structurally diverse that grouped the accessions into two subpopulations (K = 2). Therefore, this research aimed to identify potential genotypes and suitable traits of rice germplasms for breeding programs.

Salicylic acid (SA) is an important phytohormone essential for the regulation of plant growth, development, ripening, and defense responses. The role of SA in plant–pathogen interactions has attracted a lot of attention. Aside from defense responses, SA is also important in responding abiotic stimuli. It has been proposed to have great potential for improving the stress resistance of major agricultural crops. On the other hand, SA utilization is dependent on the dosage of the applied SA, the technique of application, and the status of the plants (e.g., developmental stage and acclimation). Here, the effects of exogenously applied SA (0, 0.15 and 0.30 mM) as foliar spray under nickel (Ni) stress (0 and 700 µM) in root growing medium were studied on two maize varieties (C-20 and EV-79). The experiment was conducted using a three-factor factorial design with three replicates and watering 1L Hoagland’s nutrient solution/day. Ni stress decreased the number of leaves per plant, flag leaf area, total chlorophyll contents, carotenoids, K⁺, Ca²⁺ and P accumulation in stem, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activity, while enhanced the accumulation of total soluble proteins (TSP), total phenolics, ascorbic acid contents and Na⁺ ion accumulation in both varieties of maize. Exogenously applied SA increased the number of leaves per plant, flag leaf area, chlorophyll contents, K⁺, Ca²⁺ and P accumulation, SOD, POD and CAT activity, total phenolics and ascorbic acid contents and TSP. SA application reduced the Na⁺ ion accumulation in both maize varieties. A varietal difference was observed in all attributes, and variety C-20 was proved to be more resistant as compared to variety EV-79. Overall, the research aims to contribute to the understanding of how the exogenous application of salicylic acid influenced morpho-physiological responses of maize for enhancing the tolerance of maize to heavy metal stress.

Graphic abstract

Bakanae disease in non-basmati indica rice is emerging as a major threat owing to climate change. Our objective was to identify quantitative trait loci (QTL)/gene(s) in Thavalakannan, responsible for bakanae disease resistance. A bi-parental population was developed between a resistant variety, Thavalakannan, and a susceptible variety, Pooja, to identify QTL for bakanae disease resistance. The population was challenged with a highly virulent Gerua F3 strain of the Fusarium fujikuroi pathogen in three different experiments. The percent disease incidence calculated over three experiments and the genotypic information of the population were used to identify the QTL. A main effect QTL was identified on chromosome 5 with 8.97% phenotypic variation explained. In the interval of the main effect QTL, the genes controlling gibberellic acid biosynthesis pathways were identified, indicating the significance of the QTL identified. Furthermore, seven di-QTL interactions favoring resistance were identified on different chromosomes. The main effect QTL has scope for utilization in marker-assisted introgression breeding, and interactive QTL may be utilized in genomic selection to improve disease resistance.