Develop Drought Tolerant Varieties Research Articles

Screening and growth assessment of indigenous and exotic sesame genotypes under osmotic stress

Drought stress decrease plant growth especially during germination and seedling stages in dry areas. The plants of Sesame are moderately tolerant to drought although it is sensitive at germination and seedling stages. About 102 different sesame genotypes were acquired from the Ayub Agriculture Research Institute Faisalabad Pakistan and Plant Genetic Resources Conservation Unit (USDA) Griffin Georgia United States. Including two local varieties as check screened against drought tolerant were conducted in central lab of PMAS-Arid Agriculture University Rawalpindi, Pakistan during July 2019 by using 3 levels of osmotic potential (0, -0.18, and -0.36Mpa) created through Polyethylene Glycol (PEG 8000) following the complete randomized design and data were collected on growth and early seedling indices of sesame. The Hierarchical Cluster Analysis was performed by using IBM SPSS Statistics 23 software on the basis of drought tolerance index (DTI) and Membership Function Value (MFV). Results showed significant decline by increasing osmotic potential regarding studied traits. Ten (10) drought tolerant sesame genotypes namely PI – 153509PI – 154304 PI – 158053 PI – 158059 PI – 175907 PI – 158902 PI – 164142 PI – 164317 PI – 164763 PI – 180340 were selected which exhibited the DTI value (0.451 - 0.525) with the mean MFV value ranged from (0.856 - 0.913) and 5 genotypes had DTI value ranging from (0.075 - 0.150). The genotypes with average DTI ≥ 0.525 were considered as highly drought tolerant genotypes. Contrary, the genotypes with an average DTI ≤ 0.225 were considered drought sensitive and 20 genotypes were highly drought sensitive (HDS) with mean MFV value ranged from 0.103 - 0.196. Genotypes with drought tolerance characteristics can be used for future breeding programs to develop drought tolerant varieties for increasing growth and yield of sesame in drought prone areas.

Biochemical and phenological characterization of diverse wheats and their association with drought tolerance genes

Drought is one of the most important wheat production limiting factor, and can lead to severe yield losses. This study was designed to examine the effect of drought stress on wheat physiology and morphology under three different field capacities (FC) viz. 80% (control), 50% (moderate) and 30% (severe drought stress) in a diverse collection of wheat germplasm including cultivars, landraces, synthetic hexaploid and their derivatives. Traits like grain weight, thousand grain weight and biomass were reduced by 38.23%, 18.91% and 26.47% respectively at 30% FC, whereas the reduction rate for these traits at 50% FC were 19.57%, 8.88% and 18.68%. In principal component analysis (PCA), the first two components PC1 and PC2 accounted for 58.63% of the total variation and separated the cultivars and landraces from synthetic-based germplasm. Landraces showed wide range of phenotypic variations at 30% FC compared to synthetic-based germplasm and improved cultivars. However, least reduction in grain weight was observed in improved cultivars which indicated the progress in developing drought resilient cultivars. Allelic variations of the drought-related genes including TaSnRK2.9-5A, TaLTPs-11, TaLTPs-12, TaSAP-7B-, TaPPH-13, Dreb-B1 and 1fehw3 were significantly associated with the phenological traits under drought stress in all 91 wheats including 40 landraces, 9 varieties, 34 synthetic hexaploids and 8 synthetic derivatives. The favorable haplotypes of 1fehw3, Dreb-B1, TaLTPs-11 and TaLTPs-12 increased grain weight, and biomass. Our results iterated the fact that landraces could be promising source to deploy drought adaptability in wheat breeding. The study further identified drought tolerant wheat genetic resources across various backgrounds and identified favourable haplotypes of water-saving genes which should be considered to develop drought tolerant varieties.

Effect of Water Stress on Growth and Yield Performance of Wheat Genotypes

Climate change is one of the major threats to wheat cultivation globally. Among abiotic stress, imposed by climate change, drought stress causes a drastic effect on yield and productivity of wheat. Based on this context, research was carried out on eight genotypes including WS-I (Water stress), WS-II, WS-III, WS-IV, WS-V, WS-VI, WS-VII and Khirman (check variety) to check the effect of water stress at the experimental field of Nuclear Institute of Agriculture, Tandojam. The experiment was laid-out in a split-plot design (SPD) with factorial arrangement having four treatments i.e., T1 (normal six irrigations), T2 (one irrigation), T3 (two irrigations) and T4 (three irrigations) and three replications during Rabi season, 2019-2020 in order to assess the response of wheat genotypes under different water regimes conditions for vegetative, yield and yield-related traits. The results of analysis of variance results showed that genotypes were significantly different for all traits except spike length (cm). Similarly, a significant difference was observed among the treatments for all the traits except harvest index (%). While genotype x treatments interaction showed a significance level for most of the yield associated traits except few characters such as days to 75% heading, grain filling period, plant height (cm), peduncle length (cm), spikelets spike-1 and grains spike-1 indicating that genotypes perform similarly over the treatment. Maximum mean performance for all the traits was recorded under T3 treatment compared to the T2 and T1. Among the genotypes, WS-1V perform best for grains spike-1, grain weight spike-1 (g), 1000-grain weight (g), grain yield plot-1 and harvest index (%) under all treatments. However, WS-III also performed consistently under T2 and T3 treatment. Thus, genotypes like WS-III and WS-IV could be preferred for growing in those areas where growers face the problem of water shortage. Also, WS-III and WS-IV can be used as donor genotypes for developing drought tolerant varieties.

<i>In-vitro</i> Selection of Drought Stress Tolerance in Rice (<i>Oryza sativa</i> L.) variety Tulasi and Sampada

In the present investigation, the tissue culture technique was used to develop drought tolerant varieties Tulasi and Sampada to a higher level of tolerance by two stage. First exposing the callus produced from the mature embryo to different concentrations of PEG (0.0, 1, 2 and 3) % and second selecting the best tolerant cells of the drought and obtaining plants from them. The plants tested with same concentrations of PEG, in normal conditions (pots) and evaluated by some indicators proline, carbohydrate, K, Na and Cl.

High-throughput phenotyping to dissect genotypic differences in safflower for drought tolerance.

Drought is one of the most severe and unpredictable abiotic stresses, occurring at any growth stage and affecting crop yields worldwide. Therefore, it is essential to develop drought tolerant varieties to ensure sustainable crop production in an ever-changing climate. High-throughput digital phenotyping technologies in tandem with robust screening methods enable precise and faster selection of genotypes for breeding. To investigate the use of digital imaging to reliably phenotype for drought tolerance, a genetically diverse safflower population was screened under different drought stresses at Agriculture Victoria’s high-throughput, automated phenotyping platform, Plant Phenomics Victoria, Horsham. In the first experiment, four treatments, control (90% field capacity; FC), 40% FC at initial branching, 40% FC at flowering and 50% FC at initial branching and flowering, were applied to assess the performance of four safflower genotypes. Based on these results, drought stress using 50% FC at initial branching and flowering stages was chosen to further screen 200 diverse safflower genotypes. Measured plant traits and dry biomass showed high correlations with derived digital traits including estimated shoot biomass, convex hull area, caliper length and minimum area rectangle, indicating the viability of using digital traits as proxy measures for plant growth. Estimated shoot biomass showed close association having moderately high correlation with drought indices yield index, stress tolerance index, geometric mean productivity, and mean productivity. Diverse genotypes were classified into four clusters of drought tolerance based on their performance (seed yield and digitally estimated shoot biomass) under stress. Overall, results show that rapid and precise image-based, high-throughput phenotyping in controlled environments can be used to effectively differentiate response to drought stress in a large numbers of safflower genotypes.

Impact of Irrigation on Yield Attributes of Seven Wheat Genotypes

Seven wheat genotypes i.e., PR-110, PR-112, PR-115, PR-118, PR-119, PR-120 and Pirsabak-13 were evaluated at: I0: Control, I1: irrigation at seedling stage, I2: irrigation at seedling and booting stages, I3: irrigation at seedling, tillering and booting stages and I4: irrigation at seedling, tillering, booting and grain formation stages. Among the genotypes, PR-115, PR-118 and PR-120 were found to be superior for grain yield and its related attributes under full and deficit water conditions. Irrigation at seedling + tillering + booting stages + grain formation stages (I4) produced statistically higher yield and related traits. It was also observed that in case of water shortage, irrigation at seedling and booting stages reduced the drastic losses in grain yield of wheat. The study suggested that identified promising wheat genotypes can be utilized in future breeding programs to develop drought tolerant varieties.
 Bangladesh J. Bot. 50(2): 235-243, 2021 (June)

Agronomic Performance and Genotype × Moisture Conditions Interaction for Morpho-Physiological Traits in Durum Wheat

Fourteen promising durum wheat lines, representing the elite durum germplasm for rainfed conditions, along with three check cultivars were assessed under drought and irrigated conditions for three growing seasons. The main objectives were to (i) evaluate the agronomic performance of durum wheat genotypes under different moisture stress conditions (mild, moderate, severe) and (ii) investigate the traits significantly contributing to drought tolerance. Combined ANOVA across environments for grain yield and the traits studied showed significant differences (P < 0.01) for genotype, year, moisture condition, year × moisture condition, genotype × year, and genotype × moisture condition interactions. There were differences in trait associations across the years and moisture conditions showing that the traits were significantly affected by the year and moisture conditions effects. Heading date, plant height, spike length and SPAD-reading with low ratio of σ2ge/σ2g showed a high value for heritability. Genotypes showed specific adaptation to different environmental condition as supported by significant (P < 0.01) for genotype × moisture condition interaction. Heading date, peduncle extrusion, plant height, days to maturity and 1000-kernel weight with lower genotype × moisture interaction than grain yield, were the traits contributing the most to drought tolerance. It is concluded that these traits could aid in the selection of durum wheat subject to moderate and severe stress, particularly in early generations. Under severe water stress condition, earliness to heading was an important drought escape mechanism, but inherent drought tolerance could be inferred from responses of a few genotypes. To determine effects of GE interaction on grain yield, data were subjected to GGE biplot analysis, which identified breeding lines G16, G12, G15 and G10 as the most stable and high yielding genotypes across different moisture stress conditions that can be used in convergent durum breeding program to develop drought tolerant varieties. The breeding lines which out-yielded the check cultivars are the stand out as the best promising germplasm but present different sets of favorable traits under stressed or favorable conditions.

Shortlisting putative candidate genes underlying qDTY1.1, a major effect drought tolerant QTL in rice (Oryza sativa L.).

Drought is one of the major constraints affecting rice (Oryza sativa L.) productivity and production. Conventional breeding is leading to slow progress in developing drought tolerant varieties. In this context, mapping consistent major effect QTLs and unraveling molecular basis of those QTLs will pave way for deployment of those QTLs into breeding applications. Out of more than 2500 drought tolerance related QTLs, hardly 5 to 10 QTLs have been put into breeding applications due to larger QTL window, lack of tightly linked markers and lack of knowledge on candidate genes underlying QTLs. In this present study, in silico analysis was carried out to characterize a major effect QTL qDTY1.1 region on chromosome 1 for its gene content, drought responsiveness of genes in the QTL window and metabolic functions. Out of 352 genes residing in the qDTY1.1 window, 50% of the genes were found to be drought responsive. Bioinformatics search identified precise drought responsive expression pattern of 100 genes in the QTL window. Fifty seven genes were found to be up regulated and forty three genes were found to be down regulated. The qDTY1.1 region is found to contain 23 drought responsive transcription factors such as WRKY, bZIP, NAC, AP2 and C2H2. These drought responsive genes are confirmed for the possession of drought responsive cis elements like DRE, ABRE, MYB and MYC.

Toward a New Use for Carbon Isotope Discrimination in Wheat Breeding

A major obstacle in the effort to develop drought tolerant varieties of wheat (Triticum aestivum L.) is phenotyping. Traits known to contribute to improved drought tolerance, such as water-use behavior, reliance on stem reserve carbohydrates, and the ability to develop deep roots, require time and resource-intensive screening techniques. Plant breeding programs often have many thousands of experimental genotypes, which makes testing for each of these traits impractical. This work proposes that carbon isotope discrimination (∆) analysis of mature grains may serve as a relatively high-throughput approach to identify genotypes exhibiting traits associated with drought tolerance. Using ∆ as a proxy for stomatal conductance and photosynthetic capacity, assumptions can be made regarding fundamental plant physiological responses. When combined with knowledge of the terminal drought severity experienced in a particular environment, genotypes exhibiting conservative and rapid water use, deep roots, and reliance on stem reserve carbohydrates may be identified. Preliminary data in support of this idea are presented. Further verification of this use for grain ∆ will better equip wheat breeding programs to develop more drought tolerant varieties.

Physiological Studies on Effect of Drought during Flowering in Foxtail Millet (Setariaitalica L.)

One of the major impacts of climate change is increasing the occurrence of drought, leading to drastic reduction in yield in many crop plants. Foxtail millet is thought to be an excellent experimental model in studying abiotic stress tolerance due to its small genome, conserved genome structure, short life cycle and inbreeding nature. Present study was conducted with twenty foxtail millet genotypes with objective to identify tolerant genotypes to drought under pot culture. The drought imposed by withholding irrigation for fifteen days during flowering stage and various physiological parameters measures such as, chlorophyll fluorescence, chlorophyll meter reading, relative water content, chlorophyll stability index, excised leaf water loss were measured. Among the twenty genotypes of foxtail millet, the genotypes, ISe 27, PS 4, AP 4, ISe 138 and ISe 174 were showed better results. Based on drought tolerance associated traits, genotypes were grouped as drought tolerant genotypes which could be used for breeding programme to develop drought tolerant varieties or parents for developing mapping population to identify QTL associated with drought.

Risk management in rainfed agriculture: An analysis of strategies and adaptations followed by farmers in Madhya Pradesh

Madhya Pradesh is the major producer of soybean in India. Being predominantly rainfed, the state faces high risks in its cultivation. The study undertook a primary survey in Madhya Pradesh to analyze the risk perception of farmers, elucidate the strategies followed by farmers to adapt with the risk and to identify the factors influencing their adoption. The results infer that late onset of monsoon, erratic rainfall and pest and diseases were the major risks. The major risks were related to untimely rainfall, drought and biotic factors like diseases and pest. The major adaptation strategies adopted were intercropping (49%), crop insurance (45%), micro irrigation (17%) and varietal diversification (39%). The study discerns need to develop drought tolerant varieties for rainfed regions, low cost micro-irrigation systems, enhanced credit availability to the farmers and promotion of crop insurance to adapt with production risks.

Identification of Drought Tolerant and Sensitive Species of Thyme through Some Physiological Criteria

Drought as the most important abiotic stress has deleterious effects on plants. Developing drought tolerant varieties can help produce plants in a sustainable way. This study was conducted to identify drought tolerant and drought sensitive thyme species including Thymus vulgaris, T. vulgaris (origin: Spain), T. carmanicus, T. daenensis and T. kotschyanus and to study the mechanism used by them to cope with drought stress. For this purpose, relative water content, water use efficiency, soil water depilation rate, root:shoot ratio, drought resistance index and a new criterion ceased were used. T. carmanicus and T. daenensis had the lowest and the highest reduction on relative water content, respectively. In terms of water use efficiency and soil water depletion curve, the highest and the lowest values were detected for T. daenensis and T. carmanicus, respectively. The most and the least root:shoot ratios were recorded for T. daenensis and T. vulgaris (origin: Spain), respectively. Analyses by drought resistance index and PCA revealed that T. carmanicus is drought susceptible, T. kotschyanus and T. vulgaris are semi-drought susceptible, and T. daenensis and T. vulgaris (origin: Spain) are semi-drought tolerant species. FC ceased growth analysis showed that T. carmanicus stopped its growth at higher FC, while T. kotschyanus stopped it at lower FC. Therefore, based on this criterion and considering the sustainability of growth under drought condition, T. carmanicus and T. kotschyanus are the least and the most drought tolerant Thymus species.

The emergence of a hybrid mode of knowledge production in the Generation Challenge Programme Rice Research Network (GCP-RRN) in India: Exploring the concept of Commons-Based Peer Production (CBPP)

The Generation Challenge Programme (GCP) was an international agrarian knowledge-production programme created in 2003 by the CGIAR. GCP aims at developing drought tolerant varieties by reconciling upstream biotechnology based advanced research with the downstream development at the farmer's field. The objective of this paper is to apply the theory of Commons Based Peer Production (CBPP) to analyse the knowledge production process of GCP, especially the case of drought tolerant rice research network in Indian context (GCP-RRN). CBPP represents the theorisation of a mode of production that can be distinguished from market (private) and state (public) knowledge-production systems that was developed by observing the phenomena of Free and Open Source Software (FOSS). The organisational attributes of the CBPP mode applied in computer software production include the modulation of work, small-size granularity of components, and mechanisms that integrate these modules into an end product. Socio-economically, this form of production is based on cooperation, collaboration and collective action rather than property, contract and managerial hierarchies. This paper argues that GCP-RRN knowledge production is basically a hybridised one in which there are certain inclinations towards CBPP within certain larger context, and there are other attributes too that do not fall within CBPP theorisation. Further, this paper elaborates on the implications of this hybridised model for agrarian knowledge production discourse and institutions.

Incorporation of stay-green Quantitative Trait Loci (QTL) in elite sorghum (&lt;i&gt;Sorghum bicolor&lt;/i&gt; L. Moench) variety through marker-assisted selection at early generation

Incorporation of stay-green Quantitative Trait Loci (QTL) in elite sorghum (Sorghum bicolor L. Moench) variety through marker-assisted selection at early generation.Objective: The present investigation was undertaken to develop drought tolerant varieties through introgression of stay-green QTLs in order to improve sorghum yield in semi-arid areas of Burkina Faso.Methodology and Result: Marker-assisted selection was carried out to introgress stay-green QTLs into elite sorghum variety. A stay-green donor source, BTx642 (B35), was crossed to the elite variety (Sariaso09) to obtain F1 progenies that were backcrossed to their recurrent parents to obtain the BC1F1 progenies. Seventeen flanking Simple Sequence Repeat (SSRs) polymorphic markers were used for foreground selection and 18 were used for background selection. Eighteen BC1F1 were heterozygous at all target loci for stay-green (stg1, stg2, stg3, stg4 and stgB), 5 progenies (S9B37, S9B43, S9B46 S9B85 and S9B13) had incorporated 3 of these QTLs. 4 plants (S9B34, S9B38, S9B73 and S9B16) incorporated double QTLs (Stg3 and StgB) and three plants (S9B44, S9B48 and S9B20) were heterozygous for Stg1.Conclusions and applications of findings: Among BC1F1 generation, 30 progenies had incorporated at least one stay-green QTL. Two of the introgression lines had high levels of the recurrent parents’ genomes and constitute some promising lines to develop drought tolerant varieties that will ensure sorghum production in semi-arid tropics areas and therefore, contribute to ensure food security in Burkina Faso. Despite the small number of genotypes obtained, the results showed the efficiency of Marker Assisted Back Crossing (MABC) versus the conventional backcross procedure.Keywords: sorghum, stay-green, drought, post-flowering, QTL, MABC

Effective Selection Criteria for Screening Drought Tolerant and High Yielding Bread Wheat Genotypes

Bread wheat is the major staple food in Morocco. Drought is the most important abiotic stress decreasing yield. Breeding for drought tolerance may be improved by various plant traits. In order to investigate the best selection criteria to develop drought tolerant varieties, 40 bread wheat genotypes were evaluated under two locations representing the stressed and non-stressed environments, using randomized complete block design with three replications during the cropping season 2014. Under stressed conditions, analysis of variance exhibited significant differences among grain yield, thousand kernel weight, number of plants, number of spikes and tillers per plant, plant height, plant vigor, chlorophyll content and canopy temperature; and non-significant differences for biomass, harvest index, number of days to heading and flowering, and chlorophyll fluorescence. According to correlation and principal component analysis, the grain yield was positively related with biomass, thousand grain weight, number of fertile spikes and plant vigor; and indirectly associated positively with harvest index, plant height and negatively with number of days to flowering, canopy temperature and chlorophyll content. Those traits, correlated to grain yield under stress, can be used as indirect selection for drought tolerance to obtain higher yield potential in dryland conditions. Moreover, thousand grain weight in non-stressed conditions was positively correlated to biomass, number of fertile spikes and its homologue in stressed conditions. Also, the biomass in favorable conditions was correlated to thousand grain weight and harvest index in mild stressed conditions. Thus, those two traits may be used to improve performance in drought prone environments.

English

Maize (Zea mays L.) is a major commercial crop, with high potential for production due to high solar radiation and low night temperature in sub-Saharan Africa. It is also the second most susceptible to drought among cereals, although phenotypic traits can be altered to improve drought resistance. Pot and field experiments were conducted to study the variability in root and physiological traits in different maturity groups of maize. Genotypes used were Sammaz 14, Sammaz 29, 2009 EVDT, 2009 TZE–W, TZE COMP-5 and 2009 TZEE, laid out in a Randomized Complete Block Design with 3 replications. The results obtained revealed no significant difference among the genotypes. However, the genotypes showed a good response to leaf temperature, canopy temperature, stomatal conductance and chlorophyll content. Variability was observed in three traits; days to anthesis, silking and anthesis silking interval. There was a significant correlation in leaf temperature in relation to fresh root weight, fresh shoot weight, dry shoot weight, dry root weight and shoot length. Root traits had positive relationship with grain yield. The genotypes had good rooting pattern development and combine with their physiological response they could be hybridized to develop drought tolerant varieties. Key words: Correlation, drought stress, maize, maturity group, physiological traits, roots.

Exploitation of beneficial alleles from maize (Zea mays L.) landraces to enhance performance of an elite variety in water stress environments

Yield losses of maize due to drought stress (DS) in environments with limited rains can reach 100 %. Introgression of favorable alleles from diverse landraces into adapted elite varieties will improve performance, hence reducing losses. The objective of this study was to assess the performance of BC populations under DS and multiple locations (ML) after introgression of alleles from diverse maize landraces into an elite variety. Twelve backcross (BC1F2) populations together with their recurrent parent (TZLCOMP4C1) and a commercial hybrid (Oba Super1) were evaluated under DS, well watered (WW) conditions during the dry season, and in seven ML trials in Nigeria. Significant differences were observed among genotypes for all traits except for ear aspect score under DS conditions. Grain yield and most agronomic traits measured were highly significant (p < 0.001) under WW conditions and across ML trials. In DS, eight of the 12 BC1F2 populations had similar mean grain yield compared to their recurrent parent. Four of these populations produced 3–7 % more grains than the recurrent parent. Yield improvement was accompanied by reduced barrenness, days to flowering, plant height and ear placement, and good plant and ear aspect scores. The eight BC1F2 populations should be subjected to recurrent selection under controlled DS, while four other BC1F2 populations with low grain yields could be subjected to additional backcross to increase frequency of favorable alleles for improved performance in stress environments. The resulting improved populations can be invaluable source materials for developing drought tolerant varieties and parental lines of hybrids.

Genetic variation for agronomic characters and drought tolerance among the recombinant inbred lines of wheat from the Norstar × Zagross cross

Interest in developing drought tolerant varieties is growing due to global warming. Identification of genetic variability for drought tolerance is a prerequisite to achieve this objective. In this study a sample of 28 recombinant inbred lines (RILs) of wheat developed from the cross of Norstar and Zagross varieties, together with their parents, were evaluated for two years (2010-2012) under normal and water stress conditions using split plot design with three replications. Main plots included two irrigation treatments of 70 and 140 mm evaporation from Class A pan and sub-plots consisted of 30 genotypes. The effect of genotypes and interaction of genotypes with years and water regimes were significant for all characters. Significant genotypic effect implies the existence of genetic variation among the lines under study. Heritability estimates were high for 1000 grain weight (0.87), flag leaf area (0.84), and days to heading (0.82). Biomass, grain yield, and straw yield showed the lowest heritability values (0.42, 0.50, and 0.51, respectively). Moderate genetic advance for most of the traits suggested the feasibility of selection among the RILs under investigation. Some RILs were higher yielding than either parent at both environments. Transgressive segregation was also observed for geometric mean productivity (GMP) and stress tolerance index (STI), indicating the possibility of selecting lines that are more drought tolerant than Norstar and Zagross varieties. Cluster analysis based on yield in the normal and water stress conditions, STI, and GMP identified six promising lines that can be evaluated further for drought tolerance in more environments.

Breeding for drought tolerance in crops

Tolerance to drought is under complex genetic control and selection for it often presents difficult challenges to plant breeders. With classical breeding methods, combining or pyramiding many different desirable genes in one background is nearly impossible because the tests required to reveal the presence of those genes in the off-spring are not available. The objective of this paper is to review the various approaches employed by research-ers to develop drought tolerant varieties of crop plants with emphasis on the potential of biotechnological techn-iques in addressing this concern. Screening methods for field evaluation, physiological evaluation and the use of molecular-genetic techniques have been outlined. The use of biotechnological methods provides the most op-timistic means of detecting the presence of genes conditioning drought tolerance. Biotechnological techniques also provide a better understanding of the genetic control of complexly inherited traits and lead to the developm-ent of markers that could enhance breeding for drought tolerance. Molecular markers such as isozymes, storage proteins, restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD), provide powerful means of identifying genetic loci associated with drought tolerance for use in marker-assisted selection (MAS). The development of saturated molecular genetic maps could lead to detection of markers sig-nificantly associated with quantitative trait loci (QTL) that determine drought tolerance, which could make sele-ction for drought tolerance more effective than conventional phenotypic methods. (Journal of Applied Science and Technology: 2001 6(1-2): 116-122)