Mungbean is one of the prominent pulse crops in Indonesia since the mungbean seeds are highly nutritious and has become an important part of the diet for the community. The black-seeded mungbean highly nutritious as it contains high anthocyanin content. We have developed a black-seeded mungbean lines that need to be evaluated for drought tolerance. Drought tolerance is important as mungbean is usually cultivated during the drought-prone dry season that leads to total loss. This study aimed to (1) determine the effectiveness of drought tolerance indices to select drought tolerance in black-seeded mungbean, (2) reveal the drought indices most suitable to select drought-tolerant, high- yielding black-seeded mungbean lines. This study was conducted during dry season in the Field Laboratory of Universitas Nusa Cendana. A Split-Plot design was employed, consisting of irrigation frequencies as the main plot and mungbean genotype as the sub- plot treatments. The main plot consisted of three levels, i.e. irrigation every day (I1), every four days (I2), and every seven days (I3), and the subplot consisted of 23 mungbean genotypes. Seed yields under non-stress and stress conditions were used to calculate the drought indices. The data were subjected to ANOVA, PCA and correlation analysis. There were significant variations in seed yields among genotypes under different drought indices. The indices MP, GMP, STI, HARM, MRP, SSI, YSI, MSTIK1, and MSTIK2 are suitable for selection of drought-tolerant, high-yielding mungbean lines. V9.HT, V10.HT, V11.HT, V16.HT, V18.HT, V19.HT, V20.HT, V22.HT were potential for further evaluation as promising drought tolerant, high yielding varieties.
SNP-based markers have been widely used to identify tolerant varieties harboring major genes related to abiotic stress tolerance. Here, we developed Fluidigm markers for the core set of SNPs underlying tolerance to abiotic stresses such as salinity, drought, anaerobic germination and submergence. The core set of SNPs was selected from the major genes and/or QTLs for the abiotic stresses previously reported in rice;
Citations
Drought tolerance is derived from complex quantitative traits that are associated with different shoot and root morphological characters. This study assessed the genetic and phenotypic variation of 12 maize inbred lines and performed association analysis of 11 drought-related traits using 360 simple sequence repeats (SSRs), detecting 1,604 alleles, with an average of 4.4 alleles per locus. The average values of gene diversity (GD) and polymorphism information content (PIC) were 0.648 and 0.598, respectively. In principal component analysis (PCA), shoot fresh weight (SFW), shoot dry weight (SDW), stem weight (SW), leaf weight (LW), root fresh weight (RFW), root dry weight (RDW), and leaf area (LA) traits contributed greatly to the PCA. Association analysis was performed using a general linear model with a Q-matrix (Q GLM) and a mixed linear model with Q and K-matrices (Q + K MLM). Twelve SSR markers for drought tolerance trait were detected by Q GLM, and all maize inbred lines were clearly divided into two groups in accordance with their drought tolerance. Duplicated significant marker-trait associations (SMTAs) between Q GLM and Q + K MLM identified eight marker-trait associations involving four SSR markers that were associated with the traits of SW, SFW, RFW, and RDW with a significant level of
Citations
Drought stress is a crucial environmental factor for plant survival, and the development of drought-tolerant varieties is one of the goals of all cultivated plant researchers. In particular, the seedling stage is important for plant growth and development and is also the period most affected by drought. We investigated the initial response to drought stress in seedlings of two species of poplar (
Citations
objective
of the present study was to evaluate three red maple cultivars namely, October glory, Autumn red, and Red sunset for their physiological and molecular response to drought stress. Saplings of three cultivars of red maple were subjected to drought stress (up to 28 days unirrigated) in the summer of 2018 and 2019, and leaf samples were used to quantify physiological, biochemical, and expression changes under stress. Decrement of chlorophyll content significantly correlated with the soil moisture content observed in all three genotypes subjected to drought stress. Significant variation in proline concentration, Malondialdehyde levels, and increase in superoxide dismutase (SOD) activity at various stages of the experiments showed the ability of the maple plants to respond to drought stress. RT-qPCR analyses revealed higher and variable expression of drought-responsive genes
Citations
Peanut (
Citations
The development of rice varieties that are tolerant of drought stress needs to be detected with Image-based phenotyping. This Image-based phenotyping method in combination with selection index and multivariate analysis can characterize the morphological response easily within a short time, which makes it is suitable for rice screening under drought stress. Therefore, this study aims to determine the selection index based on multivariate analysis and assess the effectiveness of using image-based phenotyping in drought rice screening. This study was conducted in two stages, the first was in static hydroponic and the second was in dynamic hydroponic. In static hydroponic, a split-plot design was used, where the levels of drought were the main plots and varieties were the subplots. However, in dynamic hydroponic, a nested design was used, where the replicates were nested in the drought level treatments. Also, The drought level factors used were PEG 0%, PEG 10%, and PEG 20%, and the variety factor consisted of 5 varieties which were repeated three times. The results showed that the selection index for static hydroponic consisted of shoot area (0.421), green shoot area (0.4177), and the area growth rate (0.4192). Meanwhile, the selection index in dynamic hydroponics consisted of object extent Y from the side (0.4516) and convex hull from the side (0.4177). The regression of the two-selection index has a good determination of 0.84. Hence, these results showed that rice screening based on image-based phenotyping can be recommended for rapid screening under drought stress.
Citations
Six durum and twelve bread wheat genotypes were evaluated under favorable and drought-stressed field conditions, and screened with thirty simple sequence repeats (SSR) markers. The traits studied were stomata frequency (STF), relative water content (RWC), flag leaf area (FLA), flag leaf weight (FLW), flag leaf dry matter content (FLD), chlorophyll a content (Chl.a), chlorophyll b content (Chl.b), grain yield/plant (GYP) and 1000-kerenl weight (TKW). Highly significant differences were observed among wheat genotypes for all the traits, indicating considerable genetic variation. Moderate to high broad-sense heritability estimates were observed for the studied traits. Under drought stress, GYP was positively correlated with RWC, FLA, FLW and TKW, whereas negatively correlated with STF. G3 (Svevo) and G6 (WK-12-1) were the most drought-tolerant durum wheat, whereas G11 (L.S-15) and G16 (SIDS-1) were the most drought-tolerant bread wheat genotypes. SSR markers analysis indicated considerable genetic variation between and within durum and bread wheat genotypes. The percentage of polymorphism ranged from 14.3% (Xgwm174-5D) to 100% (Xgwm294-2A and Xgwm573-7B), with an average of 61.4%. The polymorphism information content (PIC) ranged from 0.20 (Xwmc596-7A) to 0.48 (Xgwm294-2A), with an average of 0.33.The highest polymorphism (77.1%) was observed in the B genome followed by A (57.8%) and D (50.0%) genomes. Cluster analysis based on phenotypic data distinguished the most drought-tolerant genotypes (G6 and G11) from the remaining genotypes. Cluster analysis based on SSR markers distinguished durum from bread wheat genotypes. The study indicated that phenotypic data and SSR markers were effective in assessing the genetic diversity in the studied genotypes.
Citations
Water deficit is a critical factor obstructing the growth and survival of plant. Therefore, researchers have been trying to develop drought-resistant varieties. To find indicators of drought stress-tolerance of cypress (
Citations
Plants are often exposed to biotic and abiotic stresses that affect plant growth, development, and productivity. Drought is an important abiotic stress that has a particularly serious impact on plant growth and development. We transformed rice with
We have developed a multi-layer pipeline that uses transcriptomic data to identify candidate genes associated with complex pathways in plants. We used this multi-layer approach, incorporating microarray, RNA sequencing, polymerase chain reaction (PCR), and protein-protein interaction analyses, to identify 14 genes associated with drought tolerance in potato. We generated transgenic potato lines that over-express
Citations
Drought is one of the major abiotic factors that have a serious effect on the production of cereals crops including maize, which is grown widely in the world. Screening based on drought facilitates selection of inbred lines and an understanding of drought-tolerant traits. The effect of drought stress and rescue after stress on maize inbred lines was investigated in this study. Different plant growth attributes namely plant height, leaf area and weight, stem weight, root length, shoot and root fresh and dry weight, and total leaf chlorophyll content were measured. Six flint inbred lines (FLD 12, FLD 23, FLD 24, FLD 33, FLD 35, and FLD 37) were screened as drought-tolerant lines, whereas another six flint inbred lines (FLD 01, FLD 13, FLD 16, FLD 18, FLD 29, and FLD 31) were screened as drought susceptible lines. Growth attributes under different drought conditions were subjected to a correlation test and analysis of variance and showed highly significant relationships with each other. The drought effect differed with different inbred lines, indicating a wide variability of drought response at the early growth stage of maize plants. The results obtained from this study will be useful for selecting maize inbred lines in future breeding programs for enhancing drought tolerance.
Citations
The
objective
of this study was to detect QTLs for rice seedling traits under normal water (control) and low water conditions (drought stress). Ninety-eight recombinant inbred lines (RILs) from a cross between closely-related japonica cultivars, M-203 and M-206 were grown under both low water and normal water conditions. QTLs for morphological traits were investigated at seedling stage using 5,164 single nucleotide polymorphisms via genotyping-by-sequencing. Twenty-three QTLs were associated with four seedling traits: shoot length (SL), root length (RL), shoot dry weight (SW) and root dry weight (RW), were detected and most QTLs were clustered on chromosome 1, 6, 7 and 11. Under normal water conditions, nine QTLs for seedling traits were detected and M-203 alleles increased all the values. The locations of most QTLs were consistent with genes that regulate or respond to auxin and gibberellin. For drought tolerance, fourteen QTLs were detected including seven for drought stress conditions and seven for relative performance (values from drought stress conditions/normal water conditions). Seven QTLs from drought stress conditions coincided with the loci of previously identified drought tolerance genes. Based on the shoot and root length under drought stress conditions, five lines exhibiting the highest values in common were selected as a drought tolerance group. Those lines exhibited better growth than the parents under drought stress conditions and had QTLs alleles for drought tolerance detected in this study. QTL information and selected lines may be used for improving seedling vigor and drought tolerance of rice in breeding programs.
Citations
Seedling vigor in drought stress conditions is an important characteristic of the dry direct-seeded rice system. The drought stress in the seedling stage disrupts seed germination and delays the establishment of seedlings. However, little is known about the genetic mechanism of seedling vigor in drought conditions. The identification of quantitative trait loci (QTL) was conducted using 162 recombinant inbred lines (RILs) derived from a cross between two rice varieties—a Tongil-type Milyang23 and a temperate japonica Tong88-7. The seedling vigor of these RILs was characterized by measuring 10 morphological traits of the seedlings grown under drought conditions. The Tong88-7 seedlings showed significantly higher values than the Milyang23 seedlings for all traits. The genotyping-by-sequencing method was used to construct a map of 6140 single nucleotide polymorphisms. Six main-effect QTLs (M-QTLs) associated with seedling vigor traits under drought stress were identified on chromosomes 9 and 11. In particular, five out of these six QTLs were located on chromosome 11, explaining the phenotypic variances of 4.3% through 10.1%. In addition, 21 epistatic QTLs (E-QTLs) were detected, and the 27 loci involved in this interaction were distributed on 11 chromosomes. Both M-QTLs and E-QTLs detected in this study would be useful in breeding programs to develop elite rice varieties especially adapted to dry direct-seeded rice system.
Citations
In this study,
Citations
Drought and salinity are the major environmental constrains in global agricultural production. Plant breeding for the drought and salt tolerance needs a proper assessment procedure to overcome stress constrain. Fundamental understanding on the physiological nature of the plant tolerance provides valuable information for the genetically modified crop’s development. Drought or salt stress induces several common physiological responses in plants such as water relation and photosynthetic capacitiy. It is because both stresses lead cellular dehydration in the plants, particularly, during the early phase of stress imposition. Drought and salinity decrease CO2 availability for photosynthesis via stomatal limitation as well as elevate leaf temperature due to partially closed stomata. In this scenario, stomatal regulation and plant water status are important aspects in abiotic stress environment. These physiological responses have a function to stabilize the temperature inside plant/leaf. Therefore phenotyping through an infra-red thermography (heat sensitive sensor), could be a useful tool in the selection of a tolerant genotypes. Infra-red thermography is a part of the electromagnetic spectrum which emits a certain amount of radiation as a function of their temperatures. In general, the plants which have less water, would have higher temperature and display more infra-red radiations. In abiotic stresses such as drought and salinity, plant water status is affected and varied from the sensitive to tolerant level. Infra-red images of plants are often linked with some of the physiological attributes to the tolerance. This review covers the limits, advantages, linkages, comparison and other prospectives of using thermal imagaes in modern phenotyping techniques.
Citations
Plants have adapted the ability to respond to various abiotic stresses such as high salinity, osmotic stress, high and low temperatures, and drought in order to survive. Small heat shock proteins (sHsps) play important and extensive roles in plant defenses against abiotic stresses. Herein, we cloned an sHsp gene from the rice, which we named
Citations
Drought is one of the most important abiotic factors affecting wheat production and development of tolerant genotypes is limited by the lack of effective selection criteria. A genetic analysis of drought tolerance indices at seedling stage (i.e. root length, shoot length, root/shoot ratio and seedling dry weight) was performed for a seven-parent half diallel cross of bread wheat (
Citations
A set of five Korean rice cultivars and seven drought-tolerant indica lines were screened under irrigated non-stress and drought-stressed conditions in the 2011 and 2012 dry seasons at IRRI, Philippines. The drought-stressed experiment received mild to moderate stress. Under drought stress, ‘IR86918-B-439-B’ had the highest grain yield among all tested lines and ‘Hanarembyeo’ had the highest grain yield among the five Korean rice cultivars. ‘IR86918-B-439-B’ also had the highest yield under irrigated non-stress conditions. The grain yield of ‘Hanareumbyeo’ was similar to ‘IR86918-B-439-B’ under non-stress conditions. SSR marker analysis was performed using 125 SSR markers for detection of polymorphic markers between the Korean rice cultivars and the drought-tolerant indica lines, and for genetic diversity analysis. Twelve polymorphic markers were identified in the region of three major drought QTLs (DTY1.1, DTY2.2, DTY3.1) in two of the Korean rice cultivars and three of the drought-tolerant lines. These polymorphic markers will be useful as foreground genotyping markers for drought-QTL introgression in Korean rice genetic backgrounds.
Citations
Common wheat (
Citations