Improving Water Use Efficiency of Wheat Crop Varieties in the North China Plain: Review and Analysis

The North China Plain （NCP）, one of the most important agricultural regions in China, is facing a major water-resource crisis evoked by excessive exploitation of groundwater. To reduce water use while maintaining high crop production level, improving variety water use efficiency （WUE） is an urgent need, especially because other water-saving measures such as water delivery, irrigation, and agricultural practices have already achieved most possible progresses. Evaluation of variety WUE can be performed accurately at the individual plant level （WUEp）. Reviewing the studies on physiological factors affecting WUE p performed up to date, stomatal conductance was considered to be an important trait associating closely with WUE p . The trait showed a large degree of varietal variability under well-watered conditions. Crop varieties differ highly in sensitivity of stomata to soil and air drying, with some varieties strongly reducing their stomatal conductance in contrast with those lightly regulating their stomata. As a result, difference among varieties in WUE p was enlarged under water deficit conditions in contrast with those under well-watered conditions. The relationship between stomatal conductance and yield depends on water availability of whole growing period in local areas. Usually, large stomatal conductance results in a high yield under good irrigation system, whereas a low stomatal conductance can lead to yield benefit under limited stored soil moisture conditions. In the NCP, winter wheat is the largest consumer of irrigation water, improvement strategies for high WUE aiming at wheat crops are in urgent need. We suggest, for the well-irrigated areas with excessive exploitation of groundwater, the wheat breeding program need to combine medium stomatal conductance （0.35 mmol H2O m-2 s-1 or so）, high carboxylation efficiency, and high harvest index. Areas with partial/full access to irrigation, or infrequent drought, should target wheat varieties with high stomatal conductance under no water stress and low sensitivity of stomata to soil water deficit. Drought-prone rain-fed areas characterized by frequent and long terminal drought should target wheat varieties with low stomatal conductance under no water stress and high stomata sensitivity to soil drying to make water available during grain filling.

Multiple Impact of Integrated Watershed Management in Low Rainfall Semi-Arid Region: A Case Study from Eastern Rajasthan, India

The agriculture in low rainfall areas of eastern Rajasthan, India is characterized by high risks from drought, degraded natural resources and pervasive poverty, food insecurity and malnutrition. In this region, water is the main limiting factor for upgrading rainfed agriculture. For such areas integrated watershed management is recognized as a potential approach for agriculture growth and rehabilitation of fragile and degraded lands. At Gokulpura-Goverdhanpura village in Bundi eastern Rajasthan, India an integrated watershed project was implemented using the holistic systems approach. This paper discusses the impacts of this watershed program on bio-physical, socio-economic, environmental and ecological parameters. Results indicate that due to watershed interventions the groundwater availability has substantially increased which brought changes in cropping patterns with high value crops. Significant increases in irrigated area, cropping intensity along with diversification of crops from traditional to commercial cash crops were recorded. The watershed program also significantly improved the socio-economic status of the watershed community. It has increased the income and reduced poverty of the people in the watershed. The watershed interventions generated good employment opportunities and significantly reduced the migration of both skilled and unskilled labor from the watershed village to urban areas. It has also improved the environmental quality and ecological status in the watershed. The watershed interventions increased the vegetative index or greenery, reduced runoff, soil loss, and land degradations and improved the bio-diversity in fragile ecosystems. Overall, the integrated watershed program at Gokulpura-Goverdhanpura provided resilience by ensuring continued and sustainable multiple outputs, besides soil and water conservation and other positive environmental effects.

Sorghum germplasm from West and Gentral Africa maintained in the ICRISAT genebank: Status,gaps,and diversity

The genebank at ICRISAT maintains 8020 accessions of sorghum from 16 West and Central African countries. Geographical gaps and diversity were assessed in the collection. Using the passport data of 3991 accessions for which georeferenced data were available, a total of386 districts(gaps) located in 11 West and Central African countries were identified as geographical gaps. Burkina Faso with 140 and Nigeria with 118 districts were identified as countries with major geographical gaps. The collection of 43 accessions of wild species represented only three species belonging to Sorghum bicolor ssp. drummondii and ssp.verticilliflorum, S. hevisonii, and S. macrochaeta, highlighting the need for collection missions aimed exclusively at enriching the collection of wild relatives. Accessions having characterization data(7630) were used to assess diversity. The first three principal components contributed to >60% of variation. Maximum diversity was observed in the collection from Nigeria for both qualitative and quantitative traits. Mean values indicated significant differences between basic and intermediate races for the traits studied. Among the races, accessions of guinea-caudatum for qualitative traits and those of caudatum for quantitative traits were highly diverse. The low intensity of the sorghum collection and the many geographical gaps in the collection underline the importance of launching collection missions to fill the gaps, particularly in regions of predominantly guinea sorghums.Genotyping of possible duplicate accessions is needed to identify duplicates in the collection. It is suggested that all passport information including georeferenced data of collection sites should be collected when samples are collected in gaps.

Inter-row tillage for improved soil and water conservation and crop yields on crusted Alfisols

In the semi-arid tropics (SAT),33% areas are occupied by Alfisols and related soils. In SAT these soils have low structural stability and thereby tend to form seal and crusts at the surface. Due to this a large proportion of the rain that falls on Alfisols during the early part of the rainy season,is normally lost as runoff thus causing high soil loss as well as moisture stress to crops. Two tillage studies were conducted first at plot scale (320 m2) during 1991-95 and second at small watershed scale (1.45 ha) during 2007-10,at ICRISAT research station,Hyderabad,India. These studies were conducted to find out whether the problem of excessive runoff and soil loss during the early part of the rainy season can be controlled by various inter-row tillage systems in addition to normal intercultivation by breaking the crust or seal and thereby improving infiltration and soil moisture and reducing runoff and soil loss. The observations on rainfall,runoff,soil moisture,soil loss,soil surface roughness and crop yields were collected from both the studies. Results from these studies have shown that inter-row tillage in addition to normal intercultivation is found effective in controlling early season runoff and soil loss and increasing crop yields. The additional tillage systems are found most effective during low and medium rainfall years and not so much during high rainfall years. The additional tillage with shoe cultivators,which creates rough soil surface (11 mm depression storage),is found most effective in increasing crop yields and reducing runoff and soil loss. The additional tillage with blade harrow which generates smooth soil surface is relatively less effective. In most rainfall conditions,the normal intercultivation with one additional tillage is found adequate for controlling early season runoff and improving soil moisture and crop yields.

木豆杂种优势利用研究进展

自1974年发现木豆雄性不育株以来,国际上不断对木豆核雄性不育(GMS)和核质互作雄性不育(CGMS)基因及其种质资源进行研究和挖掘,最终实现了木豆杂种优势的成功利用。本文系统总结了过去30多年来,国际上木豆杂种优势机理、表现及授粉方式等基础研究,GMS、CGMS不育系及其配套制种体系研究,杂种优势强度研究,以及木豆杂交种生产技术研究进展。提出了木豆杂种优势利用的具体研究方向和展望。

Resistance to Aspergillus flavus in maize and peanut:Molecular biology, breeding, environmental stress,and future perspectives

The colonization of maize(Zea mays L.) and peanut(Arachis hypogaea L.) by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species(ROS) within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A.flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

Diversity and trait-specific sources for productivity and nutritional traits in the global proso millet(Panicum miliaceum L.) germplasm collection

Proso millet is an important short-duration crop that adapts well to varied climatic conditions and is grown worldwide for food,feed and fodder purposes.Owing to a lack of genetic improvement,the crop has experienced no yield improvement and provides low income to farmers.In this study,200 accessions of proso millet originating in 30 countries were evaluated in two rainy seasons to assess phenotypic diversity for morpho-agronomic and grain nutritional traits and to identify high grain-yielding and grain nutrient-rich accessions.Proso millet diversity was structured by geographical region,by country within region,and by racial group.Race patentissimum showed high diversity and ovatum low diversity,and diverged widely from each other.The lowest divergence was observed between races compactum and ovatum.Eighteen high grain-yielding,10 large-seeded,and 26 two or more grain nutrients-rich accessions were identified,and highly diverse pairs of accessions within and between trait groups were identified.They included IPm 9 and IPm2661 for high grain yield and large seed size;and IPm 2069,IPm 2076,and IPm 2537 for high Fe,Zn,Ca,and protein contents.IPm 2875 had a seed coat that is readily removed by threshing.This study provides valuable information to proso millet researchers about agronomic and nutritional traits in accessions that could be tested for regional adaption and yield for direct release as cultivars,and could be used in breeding for developing high grain-yielding and nutrient-rich cultivars.

Rapid generation advance(RGA) in chickpea to produce up to seven generations per year and enable speed breeding

This study was aimed at developing a protocol for increasing the number of generation cycles per year in chickpea(Cicer arietinum L.).Six accessions,two each from early(JG 11 and JG 14),medium(ICCV 10 and JG 16),and late(CDC-Frontier and C 235)maturity groups,were used.The experiment was conducted for two years under glasshouse conditions.The photoperiod was extended to induce early flowering and immature seeds were germinated to further reduce generation cycle time.Compared to control,artificial light caused a reduction in flowering time by respectively 8–19,7–16,and 11–27 days in early-,medium-,and late-maturing accessions.The earliest stage of immature seed able to germinate was 20–23 days after anthesis in accessions of different maturity groups.The time period between germination and the earliest stage of immature seed suitable for germination was considered one generation cycle and spanned respectively 43–60,44–64,and 52–79 days in early-,medium-,and late-maturing accessions.However,the late-maturing accession CDCFrontier could not be advanced further after three generation cycles owing to the strong influence of photoperiod and temperature.The mean total number of generations produced per year were respectively 7,6.2,and 6 in early-,medium-,and late-maturing accessions.These results have encouraging implications for breeding programs:rapid progression toward homozygosity,development of mapping populations,and reduction in time,space and resources in cultivar development(speed breeding).

Barnyard millet global core collection evaluation in the submontane Himalayan region of India using multivariate analysis

Barnyard millet(Echinochloa spp.) is one of the most underresearched crops with respect to characterization of genetic resources and genetic enhancement. A total of 95 germplasm lines representing global collection were evaluated in two rainy seasons at Almora,Uttarakhand, India for qualitative and quantitative traits and the data were subjected to multivariate analysis. High variation was observed for days to maturity, five-ear grain weight, and yield components. The first three principal component axes explained 73% of the total multivariate variation. Three major groups were detected by projection of the accessions on the first two principal components. The separation of accessions was based mainly on trait morphology. Almost all Indian and origin-unknown accessions grouped together to form an Echinochloa frumentacea group. Japanese accessions grouped together except for a few outliers to form an Echinochloa esculenta group. The third group contained accessions from Russia, Japan, Cameroon, and Egypt. They formed a separate group on the scatterplot and represented accessions with lower values for all traits except basal tiller number. The interrelationships between the traits indicated that accessions with tall plants, long and broad leaves, longer inflorescences, and greater numbers of racemes should be given priority as donors or parents in varietal development initiatives. Cluster analysis identified two main clusters based on agro-morphological characters.

Diversity, abundance, and structure of tree communities in the Uluguru forests in the Morogoro region, Tanzania

Uluguru forests are globally recognized as important biodiversity hotspots, but anthropogenic pressure threatens their value. This study examined species diver- sity, abundance, and structure of trees in the Uluguru for- ests. All trees of diameter at breast height （DBH） 〉 10 cm were inventoried in seven forests ranging from 3 to 995 ha in area. A total of 900 stems, 101 species and 34 families were inventoried. Fabaceae was the most speciose family. Ehretia amoena Klotzsch was the most abundant species with relative abundance of 9.22 %. The forests differed significantly in species richness （26-93 species ha-l）, tree density （85-390 stems ha-l）, basal area （3-24 m2 ha-1） and Shannon-Wiener diversity （2.50--4.02）. Forest area was significantly and positively correlated with species richness （r = 0.92） and species diversity （r = 0.95）. Tree density showed significant positive correlation with speciesrichness （r = 0.80） and basal area （r = 0.85）. Milawilila and Nemele forests had highest floristic similarity （0.55） followed by Kimboza and Kilengwe （0.54） while the rest had similarity coefficients of less than 0.50. Despite leg- islative protection, many forests remain at risk and there- fore the possibility to conserve highly valuable tree species via enhanced protection or cultivation must be considered.

Improvement of three popular Indian groundnut varieties for foliar disease resistance and high oleic acid using SSR markers and SNP array in marker-assisted backcrossing

Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it increases the shelf life of the produce/products in addition to providing health benefits to consumers.Marker-assisted backcrossing(MABC)is the most successful approach to introgressing or pyramiding one or more traits using traitlinked markers.We used MABC to improve three popular Indian cultivars(GJG 9,GG 20,and GJGHPS 1)for foliar disease resistance(FDR)and high oleic acid content.A total of 22 BC3F4 and 30 BC2F4 introgression lines(ILs)for FDR and 46 BC3F4 and 41 BC2F4 ILs for high oleic acid were developed.Recurrent parent genome analysis using the 58 K Axiom_Arachis array identified several lines showing upto 94%of genome recovery among second and third backcross progenies.Phenotyping of these ILs revealed FDR scores comparable to the resistant parent,GPBD 4,and ILs with high(~80%)oleic acid in addition to high genome recovery.These ILs provide further opportunities for pyramiding FDR and high oleic acid in all three genetic backgrounds as well as for conducting multi-location yield trials for further evaluation and release for cultivation in target regions of India.

Patterns of Molecular Diversity in Current and Previously Developed Hybrid Parents of Pearl Millet [<i>Pennisetum glaucum</i>(L.) R. Br.]

ICRISAT’s pearl millet (Pennisetum glaucum (L.) R. Br.) breeding program at Patancheru, India, has developed genetically diverse hybrid parents since 1980s. The present study investigated genetic diversity pattern between two groups of parents in this program, bred till 2004 and developed during 2004-2010. Combined analysis of 379 hybrid parents (current 166 parents and 213 previously developed hybrid parents) carried out using a set of highly polymorphic 28 SSRs detected 12.7 alleles per locus. An average of 8.5 and 8.7 SSR alleles per locus were found in previously developed and current parents, respectively, indicating marginal improvement in the levels of genetic diversity of hybrid parents in this program. Distance matrix differentiated these current and previously developed hybrid parents into 2 separate clusters, indicating infusion of new genetic variability over time as reflected by development of more genotype-specific alleles. Also, the seed and restorer parents were found clearly separated from each other in both the sets with few crossovers, indicating existence of two diverse and broad-based pools in hybrid parents of pearl millet. Restorer parents (R-lines) were found more diverse than seed parents (B-lines), as higher average gene diversity was detected among R-lines (0.70) than B-lines (0.56), though variation between B- and R-lines was found reduced in newly developed lines to 9.22% from 16.98% in previously developed lines. Results suggested that newly developed lines were as much divergent when compared with previously developed lines, indicating that current ICRISAT pearl millet breeding program was moving towards development of diverse new hybrid parental lines. The study suggested use of trait-specific donors in B- and R-lines separately to maintain sufficient genetic distance between seed and restorer breeding lines. It was pointed out to cross parents having higher genetic distance within the seed (B-lines) and restorer (R-lines) breeding programs to derive diverse and productive hybrid parental lines in future.

Soil Erosion Control and Moisture Conservation Using Contour Ridge Tillage in Bougouni and Koutiala, Southern Mali

Soil erosion is among the critical environmental constraint for crop production in southern Mali. Contour ridge tillage (CRT), a water conservation technique had been locally applied since 1990. The objective of this study was to determine the effects of CRT compared with farmer conventional agriculture practice (NoCRT) on runoff, soil loss, nutrient loss, moisture conservation and cereals yields under rainfed conditions in two Southern Mali sites, in 2016 and 2017 in farmer fields. Measurements were performed on erosion plots composed of CRT and NoCRT plots from which water samples were collected to determine sedimentation levels, concentration and nutrients losses using pairwise comparison. Average runoff coefficient in NoCRT plots was 35.62% compared to 19.25% for the CRT plots explaining a runoff reduction of 46%. Mean soil losses of 12,095 t·ha-1 and 4970 t·ha-1 were respectively measured in NoCRT and CRT plots. Losses in calcium, magnesium and potassium nutrients in the NoCRT plots were 80%, 66%, 75% higher compared to CRT ones, respectively. Sorghum grain yield was at least two folds higher in CRT plots compared to the NoCRT plots. Maize average grain yield was 87% higher in CRT plots than in the NoCRT. For sustained soil productivity, CRT is advocated as a better soil and water management technique than the NoCRT one.

Intra-population genetic variance for grain iron and zinc contents and agronomic traits in pearl millet

Crop biofortification is a sustainable approach for fighting micronutrient malnutrition in the world. The estimation of variance components in genetically broad-based populations provides information about their genetic architecture, allowing the design of an appropriate biofortification breeding method for cross-pollinated crops such as pearl millet. The objective of this study was to estimate intra-population genetic variance using self(S1) and half-sib(HS) progenies in two populations, AIMP92901 and ICMR312. Field trials were evaluated in two contrasting seasons(2009 rainy and 2010 summer; otherwise called environments) in Alfisols at ICRISAT, Patancheru. Analyses of variance showed highly significant variation for S1 s and HS progenies, reflecting high within-population genetic variation for both micronutrients and other key traits. However, the HS showed narrow ranges and lower genetic variances than the S1 for all of the traits. The micronutrients were highly positively correlated in S1(r = 0.77 to 0.86; P < 0.01) and HS(r = 0.74 to 0.77; P < 0.01)progenies of both populations, implying concurrent genetic improvement for both micronutrients. The genetic variance component was different among populations for Fe and Zn contents across environments, with AIMP92901 showing a greater proportion of dominance and ICMR312 greater additive variance for these micronutrients. The estimates of variance(additive and dominance) were specific for each population, given their dependence on the additive and dominance effects of the segregating loci, which also differ among populations. The possible causes for such differences were discussed. The results showed that the expression of these micronutrients in pearl millet shows largely additive variance, so that breeding high-iron hybrids will require incorporation of these micronutrient traits into both parental lines.

Phenotypic and molecular diversity-based prediction of heterosis in pearl millet(Pennisetum glaucum L.(R.)Br.)

Genetic distances between hybrid parents based on phenotypic traits and molecular markers were investigated to assess their relationship with heterosis for grain and stover yield and other traits in pearl millet(Pennisetum glaucum [L.] R. Br.). Fifty-one hybrids developed using 101 hybrid parents(B and R lines) and showing a wide range of genetic distance between their parents based on eight phenotypic traits and 28–38 SSRs were evaluated in two sets for two seasons. The correlation between Euclidean distance(phenotypic distance, ED) and simple matching distance(molecular distance, SM) for parents of both sets was low but positive and significant(r = 0.2, P < 0.001).The correlation of ED in parents with better-parent heterosis for grain yield was similar in both sets(r =0.38, P < 0.05). SM was not correlated with heterosis for grain yield in either set of hybrids.The results showed that phenotypic distance could be a better predictor of heterosis than molecular distance. The correlation between phenotypic distance and heterosis was not strong enough to permit the use of phenotypic diversity among parents as a major selection criterion for selection of parental lines displaying high levels of heterosis for grain and stover yield in pearl millet.

Geographic patterns of genetic diversity and fertility restoration ability of Asian and African origin pearl millet populations

A set of 45 diverse Asian and African origin/bred populations of pearl millet were investigated multi-locationally for morphological traits including grain yield and assessed for their fertility restoration ability on three cytoplasmic male sterility(CMS) systems in two contrasting seasons. Significant genetic variation was found for all the yield linked traits. Multivariate analysis for grain yield and its component traits grouped these populations into five clusters. Most of the Asian origin populations grouped into single cluster(Cluster III) and separated from the rest of the African origin populations indicating the presence of correspondence between clustering pattern and geographical origin of the populations. Clusters dominated with Asian populations(As-As) had linkages with early flowering, short plant height, more number of tillers, small and thin panicles, small seeded and low grain yield compared to the clusters dominated by African populations(Af-Af) or African origin and Asian bred(Af-As) populations.Genetically related populations having common parentage were found grouped in same clusters.Fertility restoration/maintainer frequency of 45 populations on three diverse CMS systems revealed that overall fertility restoration frequency was highest for A1(86%) followed by A4(37%) and for A5(7%) CMS system. Five populations were identified as potential sources for developing maintainer lines for all three CMS systems and eight populations were identified specifically for A;and A;CMS systems. A set of 11 and four populations were identified for restorer line development exclusively for A;and A;CMS system,respectively. Six populations were identified for the development of dual restorers for both A;and A;CMS system.

Nature of Gene Action and Maternal Effects for Pod Borer, <i>Helicoverpa armigera</i>Resistance and Grain Yield in Chickpea, <i>Cicer arietinum</i>

Information on mechanisms and inheritance of resistance is critical to plan an effective strategy to breed for resistance to insect pests. Therefore, we evaluated a diverse array of chickpea genotypes (eight desi and one kabuli) with varying levels of resistance to the pod borer, Helicoverpa armigera to gain an understanding of the nature of gene action and possible maternal effects. The test genotypes were crossed in all possible combinations for a full diallel. The 72 F1s (36 direct and 36 reciprocal crosses) along with the parents were evaluated for resistance to H. armigera under field conditions, and for antibiosis mechanism of resistance (larval survival and larval weight gain) by using detached leaf assay under laboratory conditions, and grain yield under un-protected conditions in the field. Additive gene action governed the inheritance of resistance to H. armigera, while non-additive type of gene action was predominant for inheritance of antibiosis component of resistance (larval survival and larval weight) and grain yield. Greater magnitude of σ2 A(17.39 and 1.42) than σ2 D (3.93 and 1.21) indicated the preponderance of σ2 Ain inheritance of resistance to pod borer, H. armigera under laboratory and field conditions, respectively. There were no maternal effects for inheritance of resistance to pod borer and grain yield. Lines with significant gca effects for pod borer damage and grain yield were identified for further use in the resistance breeding program. The implications of the inheritance pattern of pod borer resistance and grain yield are discussed in the context of strategies to enhance pod borer resistance and grain yield in chickpea.

Cloning, Expression Pattern Analysis and Subcellular Localization of Resveratrol Synthase Gene in Peanut (<i>Arachis hypogaea</i>L.)

Resveratrol synthase (RS) is a key enzyme that plays a critical role in the resveratrol synthesis pathway. In this study, six RS genes were isolated and characterized from peanut variety “Zhenzhu Hong” by silico cloning and RT-PCR. Bioinformatics analysis showed that deduced amino acid sequences of the six cloned RS genes were highly conserved with a similarity from 95% to 99% when compared to the RS genes which had been deposited at the GenBank. The results of amino acid sequences analysis showed six RS proteins contained the Chal_Sti_Synt_N and ACP_Syn_III_C domains and can be classified to same family but with different evolutionary distance. Expression pattern analysis by QRT-PCR provided evidence indicating that the mRNA of six RS genes were primarily expressed in the peanut shell at different developmental stages with different expression levels, but only lower levels of them were evident in the peanut kernel. The subcellular localization of RS protein in onion epidermal cell was performed by Agrobacterium tumefaciens-mediated transformation and the green fluorescent was monitored by confocal fluorescence microscopy. The results indicated that, RS1 and RS5 were located in the nucleus and plasma membrane respectively, while the RS2, RS3, RS4 and RS6 were located in both nucleus inner membrane and plasma membrane. The data will provide basic information for elucidating the regulatory mechanisms and enzyme kinetics underlying the RS genes in the resveratrol synthase pathway.

Occurrence of <i>Alternaria alternata</i>causing Alternaria blight in pigeonpea in India

Blight symptoms on pigeonpea were observed in alarming proportion since 2009 onwards in Andhra Pradesh state of India. Alternaria blight infected pigeonpea plants were collected from Andhra Pradesh state of India to isolate and characterize the pathogen. The isolate proved pathogenic on pigeonpea cultivar ICPL 87119. Genetic characteristics were analyzed based on the sequence of the rDNA-internal transcribed spacer (ITS) region. The phylogenetic tree based on rDNA-ITS analysis showed that the Alternaria alternata causing Alternaria blight in pigeonpea is very distinct from the other Alternaria isolate reported from different host. This is the first report of molecular identification of Alternaria alternata causing Alternaria blight in pigeonpea.