Breeding French Bean (Phaseolus vulgaris L.) for Resistance to Rust (Uromyces phaseoli Reben Wint.)

French bean is an important legume vegetable grown for its tender, green pods for both fresh consumption and processing. Rust, caused by Uromyces phaseoli, limits successful cultivation of this crop. Popular varieties like Contender, Pant Anupama, Pusa Parvathi, Arka Komal, Arka Suvidha, etc., are susceptible to this disease. The french bean variety, Arka Bold, having resistance to rust was used in hybridization with Arka Komal, a popular bush variety with high yield and slender, long green pods but susceptible to rust. Inheritance studies indicated that resistance to rust was controlled by a single, dominant gene. Pedigree method of breeding was followed for incorporating rust resistance in to commercially cultivated varieties. Breeding lines with resistance to rust were selected to F2 generation onwards. These were advanced up to F7, wherein, a promising line, (Arka Bold x Arka Komal) 99-17-2-1-4-12-3, with resistance to rust with high pod yield and good pod quality was selected and named Arka Anoop and released for commercial cultivation

SCREENING OF GENOTYPES AND EFFECT OF FUNGICIDES AGAINST PURPLE BLOTCH OF ONION

ABSTRACT Three nonsystemic fungicides viz., mancozeb, iprodione and copperoxychloride and three systemic fungicides viz., difenconazole, kitazin and propiconazole were evaluated against Alternaria porri causing purple blotch of onion under invitro conditions. Among systemic fungicides tested difenconazole at 0.1 percent showed 98.85 per cent inhibition of the fungus while among the non-systemic fungicides mancozeb at 0.3 per cent was best in inhibiting the growth of Alternaria porri with 100 percent inhibition. Screening of onion genotypes for purple blotch under field condition of onion revealed that, the genotype Arka Kalyan was found moderately resistant while the genotypes viz., Rampur Rose, Agrifound Rose, Arka Pragati, Arka Niketan, Arka Pitamber and Arka Bindu were found moderately susceptible to purple blotch of onion

Antifungal activity and isomerization of octadecyl p-coumarates from Ipomoea carnea subsp. fistulosa

Not AvailableBioassay monitored HPLC assisted isolation and purification of the chief antifungal fraction of the leaves of Ipomoea carnea subsp. fistulosa (Convulvulaceae) were achieved using Colletotrichum gloeosporioides and Cladosporium cucumerinum as test organisms. The activity of the purified fraction was further confirmed by the dose dependent inhibition of the spore germination of Alternaria alternata and A. porri. The active fraction was identified as a mixture of (E)-octadecyl p-coumarate and (Z)-octadecyl p-coumarate. The two isomers were detected on an HPLC column with substantially different retention times, but once eluted from the column, one form was partly converted to the other in daylight. Conclusive evidence for the structures and their isomerization were obtained from the HPLC behavior, IR, UV, HRESIMS, CIMS and NMR spectral data. Important 1H NMR and 13C NMR signals could be separately assigned for the isomers using 2D NMR techniques.Not Availabl

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Antifungal activity of Mucuna pruriens Seed Extractives and L-DOPA

Not AvailableThe seeds of Mucuna pruriens (L.) D.C. (Leguminosae) were extracted first with hexane, then with ethyl acetate, and finally with methanol. The solvents were removed to get the respective extractives. These were assessed for the mycelial growth inhibition of three phytopathogenic fungi - Colletotrichum gloeosporioides, Colletotrichum capsici, and Fusarium solani - by the poisoned - food technique. Methanol extractive showed highest activity against all the three test organisms. L - dopa [3 - (3,4 - Dihydroxyphenyl) - L - alanine], which was qualitatively detected in the ethyl acetate and methanol extractives and quantitatively assessed in the seeds, showed antifungal activity against all the three test organisms, showing that it is one of the active principles in these extractives.Not Availabl

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Not AvailableAntifungal activity assay of the methanol extract of the aerial parts of the plant Andrographis paniculata revealed that it exhibits mycelial growth inhibition of Fusarium solani and spore germination inhibition of Alternaria solani. Pure andrographolide present in the methanol extract also exhibited spore germination inhibition of A. solani. Quantitative estimation of andrographolide in the methanol extract by HPLC revealed that it had 6.82% andrographolide in it. This is probably the first report on the antifungal activity of andrographolide.Not Availabl

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Not AvailableDried latex (aloe drug) and extractives of aloe vera obtained by hexane, ethyl acetate and methanol were tested with the aim of assessing their activity against some phytopathogenic fungi and understanding the chemical nature of the active principles present in them. The activity of the extractives against Colletotrichum gloeosporioides, Colletotrichum capsici and Fusarium solani was assessed by poisoned food technique and their activity against Cladosporium cucumerinum was assessed by thin layer chromatographic bioautography. Polar extractives obtained by methanol and ethyl acetate showed higher activity than non-polar extractive obtained by hexane. The extractives showed higher activity against Colletotrichum species than F. solani. Two constituents namely aloin and aloe-emodin were identified as active principles by their activity against Colletotrichum gloeosporioides and Cladosporium cucumerinum.Not Availabl

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Not AvailableHexane, ethyl acetate and methanol extractives of Coleus forskohlii roots exhibit mycelial growth inhibition of Colletotrichum gloeosporioides and spore germination inhibition of Alternaria solani. Forskolin, a diterpene present in C. forskohlii exhibit dose dependent spore germination inhibition of A. solani, this being the first report on the antifungal activity of this compound. Estimation of forskolin in the extractives by HPLC showed that while hexane extractive contained 3.9% forskolin and ethyl acetate extractive contained 4.6% forskolin, while the methanol extractive did not contain forskolin. The results clearly show that forskolin is one of the antifungal compounds present in the plant.Not Availabl

Chitinase gene construct from <em>Trichoderma harzianum</em> proved effective against onion purple blotch caused by <em>Alternaria porri</em>

50-56Purple blotch caused by Alternaria porri (Ellis) Ciffis the most devastating disease of onion prevalent in different parts of the country. In the absence of a resistant variety in the gene pool, gene transfer technique becomes appropriate as an alternative tool for genetic improvement. Accordingly, chitinase gene especially from the biocontrol agent Trichoderma harzianum Rifai which is used against several fungal pathogens was selected as the candidate gene. Onion transformation is difficult and Allium species are recalcitrant to transformation. Hence, before using this gene for transforming onion for conferring resistance/tolerance to Alternaria porri, chitinase gene was validated against purple blotch pathogen in a model plant system, tobacco. Tobacco transformants with T. harzianum chitinase (Th-chit) gene under the control of a strong constitutive CaMV 35S promoter with NPT-II selection marker were generated. The presence and expression of the transgene was confirmed through PCR and RT-PCR analysis, respectively. Bioassay of primary transgenic plants against A. porri through in vitro detached leaf bioassay revealed significant reduction in lesion size ranging from 73 - 100% as well as mycelial inhibition to the extent of 25 - 65% over the control (untransformed) plants. The results suggest that chitinase gene from T. harzianum can be used as a candidate gene for conferring resistance to A. porri in onion