Introgression of productivity and other desirable traits from ricebean (Vigna umbellata) into black gram (Vigna mungo)

Crosses were performed to introgress genes for productivity and other desirable traits from ricebean (Vigna umbellata) into black gram (Vigna mungo). Crossability was very poor in black gram × ricebean crosses, and only two to nine true hybrid plants were obtained. Plant fertility was very poor in initial generations, but was improved gradually from F2 onwards. Twenty-four uniform progenies, bulked in F7, were evaluated for yield potential. The percentage increase/decrease in yield ranged from −35.48 to 50.31 over the check cultivar (‘Mash338’, female parent). All the progenies were found resistant to Mungbean yellow mosaic virus, Cercospora leaf spot and Bacterial leaf spot diseases. Overall, it was found that desirable traits such as high pod number, seed weight, productivity and resistance to diseases have been introgressed successfully into black gram from ricebean. A derivative line, KUG114, recorded yield superiority of 39.45% over the check cultivar ‘Mash338’ on the average of 14 multilocation research trials. It was released under the name ‘Mash114’ for cultivation in the Punjab state

Urdbean variety Mash 391

Mash 391, an urdbean (Vigna mungo L. Hepper) variety was developed by Pulses Section, Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana. It was identified by the All India Group Meet of MULLaRP and Pigeonpea Workers held on May 16-18, 2010 at CSKHPKV, Palampur. This variety was released and notified by the Central Sub- Committee on Crop Standards Notification and the Release of the vaieties for Agricultural Crops Govt. of India vide notification Number 3-8/2010-SD-IV dated January 11, 2011 for commercial cultivation in South Zone consisted of Karnataka, Andhra Pradesh, Orissa and Tamil Nadu states in summer season..

Genetics of bushy growth habit and its implications in chickpea improvement

Chickpea (Cicer arietinum L.) plant is generally erect, semi-erect, spreading, semi-prostrate or prostrate (mainly wild annual Cicer species) in growth habit depending on the angle of branches arises from the vertical axis. Spontaneous mutations are the source of genetic variability and have resulted into dwarf erect compact type plants with high number of branches arising from base, commonly called as “bushy mutants” in chickpea [1-3]. In a study [4], it was reported that mean yield of the lines with bushy growth habit, across all environments, was higher than that of the erect habit lines..

Combining Ascochyta blight and Botrytis grey mould resistance in chickpea through interspecific hybridization

Ascochyta blight (AB) caused by Ascochyta rabiei (Pass.) Labr. and Botrytis grey mould (BGM) caused by Botrytis cinerea (Pers. ex Fr.) are important diseases of the aerial plant parts of chickpea in most chickpea growing areas of the world. Although conventional approaches have contributed to reducing disease, the use of new technologies is expected to further reduce losses through these biotic stresses. Reliable screening techniques were developed: ‘field screening technique’ for adult plant screening, ‘cloth chamber technique’ and ‘growth chamber technique’ for the study of races of the pathogen and for segregating generations. Furthermore, the ‘cut twig technique’ for interspecific population for AB and BGM resistance was developed. For introgression of high levels of AB and BGM resistance in cultivated chickpea from wild relatives, accessions of seven annual wild Cicer spp. were evaluated and identified: C. judaicum accessions 185, ILWC 95 and ILWC 61, C. pinnatifidum accessions 188, 199 and ILWC 212 as potential donors. C. pinnatifidum accession188 was crossed with ICCV 96030 and 62 F9 lines resistant to AB and BGM were derived. Of the derived lines, several are being evaluated for agronomic traits and yield parameters while four lines, GL 29029, GL29206, GL29212, GL29081 possessing high degree of resistance were crossed with susceptible high yielding cultivars BG 256 to improve resistance and to undertake molecular studies. Genotyping of F2 populations with SSR markers from the chickpea genome was done to identify markers potentially linked with AB and BGM resistance genes. In preliminary studies, of 120 SSR markers used, six (Ta 2, Ta 110, Ta 139, CaSTMS 7, CaSTMS 24 and Tr 29) were identified with polymorphic bands between resistant derivative lines and the susceptible parent. The study shows that wild species of Cicer are the valuable gene pools of resistance to AB and BGM. The resistant derivative lines generated here can serve as good pre-breeding material and markers identified can assist in marker assisted selection for resistance breeding

Combining Ascochyta blight and Botrytis grey mould resistance in chickpea through interspecific hybridization

Ascochyta blight (AB) caused by Ascochyta rabiei (Pass.) Labr. and Botrytis grey mould (BGM) caused by Botrytis cinerea (Pers. ex Fr.) are important diseases of the aerial plant parts of chickpea in most chickpea growing areas of the world. Although conventional approaches have contributed to reducing disease, the use of new technologies is expected to further reduce losses through these biotic stresses. Reliable screening techniques were developed: ‘field screening technique’ for adult plant screening, ‘cloth chamber technique’ and ‘growth chamber technique’ for the study of races of the pathogen and for segregating generations. Furthermore, the ‘cut twig technique’ for interspecific population for AB and BGM resistance was developed. For introgression of high levels of AB and BGM resistance in cultivated chickpea from wild relatives, accessions of seven annual wild Cicer spp. were evaluated and identified: C. judaicum accessions 185, ILWC 95 and ILWC 61, C. pinnatifidum accessions 188, 199 and ILWC 212 as potential donors. C. pinnatifidum accession188 was crossed with ICCV 96030 and 62 F9 lines resistant to AB and BGM were derived. Of the derived lines, several are being evaluated for agronomic traits and yield parameters while four lines, GL 29029, GL29206, GL29212, GL29081 possessing high degree of resistance were crossed with susceptible high yielding cultivars BG 256 to improve resistance and to undertake molecular studies. Genotyping of F2 populations with SSR markers from the chickpea genome was done to identify markers potentially linked with AB and BGM resistance genes. In preliminary studies, of 120 SSR markers used, six (Ta 2, Ta 110, Ta 139, CaSTMS 7, CaSTMS 24 and Tr 29) were identified with polymorphic bands between resistant derivative lines and the susceptible parent. The study shows that wild species of Cicer are the valuable gene pools of resistance to AB and BGM. The resistant derivative lines generated here can serve as good pre-breeding material and markers identified can assist in marker assisted selection for resistance breeding

Red rot resistant transgenic sugarcane developed through expression of β-1,3-glucanase gene.

Sugarcane (Saccharum spp.) is a commercially important crop, vulnerable to fungal disease red rot caused by Colletotrichum falcatum Went. The pathogen attacks sucrose accumulating parenchyma cells of cane stalk leading to severe losses in cane yield and sugar recovery. We report development of red rot resistant transgenic sugarcane through expression of β-1,3-glucanase gene from Trichoderma spp. The transgene integration and its expression were confirmed by quantitative reverse transcription-PCR in first clonal generation raised from T0 plants revealing up to 4.4-fold higher expression, in comparison to non-transgenic sugarcane. Bioassay of transgenic plants with two virulent C. falcatum pathotypes, Cf 08 and Cf 09 causing red rot disease demonstrated that some plants were resistant to Cf 08 and moderately resistant to Cf 09. The electron micrographs of sucrose storing stalk parenchyma cells from these plants displayed characteristic sucrose-filled cells inhibiting Cf 08 hyphae and lysis of Cf 09 hyphae; in contrast, the cells of susceptible plants were sucrose depleted and prone to both the pathotypes. The transgene expression was up-regulated (up to 2.0-fold in leaves and 5.0-fold in roots) after infection, as compared to before infection in resistant plants. The transgene was successfully transmitted to second clonal generation raised from resistant transgenic plants. β-1,3-glucanase protein structural model revealed that active sites Glutamate 628 and Aspartate 569 of the catalytic domain acted as proton donor and nucleophile having role in cleaving β-1,3-glycosidic bonds and pathogen hyphal lysis

Structural model showing protein-ligand interaction.

<p>β-1,3-glucanase protein (GenBank Accession No. AIC32930) docked with D-glucose.</p

Quantitative RT-PCR analysis.

<p>Relative <i>β-1</i>,<i>3-glucanase</i> expression of RT-PCR positive CG₁ plants. Bars represent range of 2^{- ΔΔC}_T.</p

Scanning electron micrographs of stalk sections from CG₁ transgenic and NT plants following inoculation with <i>C</i>. <i>falcatum</i>.

<p><b>A</b> Sucrose-filled parenchyma cells of non-inoculated NT plant (control). Arrow indicates the characteristic turgid cell. Bar represents 20 μm. <b>B</b> Presence of normal Cf 09 fungal hyphae in parenchyma cells of susceptible NT plant. Arrow indicates the sucrose depleted cell. Bar represents 20 μm. <b>C</b> Parenchyma cells of transgenic plant moderately resistant to Cf 09. Arrow indicates abnormal fungal hypha and amorphous debris. Bar represents 100 μm. <b>D</b> Sucrose-filled parenchyma cells of transgenic plant resistant to Cf 08 showing absence of hyphae. Arrow indicates the turgid cell. Bar represents 100 μm.</p