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Root exudates of sorghum plants collected via root exudates trapping system after proper fractionation, give rise a total of five allelofractions of different polarity range i.e. polar to non-polar. The fractions were found to enrich about one major compound in each which was extracted out in purity of 95% by repeatedly following the fractional crystallization and column chromatographic techniques. All these five compounds viz. C, B, A, E and D were converted to three Emulsifiable Concentrate (EC) and two Emulsive Water (EW) formulations. Laboratory bioassay experiments conducted during 2009 and 2010 at IIPR, Kanpur revealed that the Polarity of the compounds used in formulations play key role in imparting toxicity against second stage juveniles (J2) of Meloidogyne javanica. EC formulation of fractions C and B (non-polar) was found 100% toxic to the juveniles at 300 and 700 μg ml-1 concentrations, respectively at the 24 and 48 hours of incubation. EC and EW formulations of the fractions A and E (medium polarity) showed 100% toxicity at 1100 and 1500 μg ml-1 concentrations respectively, at an incubation period of 72 h, while EW formulation of fraction D (completely polar) found almost ineffective in all its test concentrations ranging from 1000-2000 μg ml-1. EC of C (highly non-polar) at 250 μg ml-1 also retarded in egg hatching of test nematode up to the extent of 98%. IR, 1HNMR, 13CNMR of C and B showed flavanol skeleton as a basic chemical moiety in their chemical structures, however, both differ structurally in respect of their functional substituents and the position of attachment at flavanol skeleton. [ABSTRACT FROM AUTHOR]

Inheritance of protruded stigma in black gram [Vigna mungo (L.) Hepper] was investigated in the F1, F2, and F3 generations of four crosses and their reciprocals involving a natural flower mutant with its parent genotype (IPU 99-167) and three other genotypes (PLU 710, Type 9, and Barabanki local). The outcrossing in the mutant was due to a flower mutant with protruded stigma and crumpled petals, thus presenting a physical condition for functional male sterility. The mutant plants appeared in the parent population at an average frequency of 3.05%. The F1 plants showed normal flowers with normal pod and seed set. The segregation analysis of F2 and F3 populations indicated a single recessive gene conditioning protruded stigma and crumpled petals with pleiotropic effect. The gene symbol stg1stg1 is proposed for this mutation. Under natural conditions in the crossing block, 100% of the seeds obtained from the mutant plants were the result of cross pollination despite 93.6% pollen viability. However, the number of seeds produced by the mutant was 92% less than normal plants. Although the mutant genotype provides a mechanism for outcrossing, unless the poor seed set can be improved (e.g., by delayed planting), its use in exploiting heterosis and population improvement will be limited. [ABSTRACT FROM AUTHOR]

Root–knot nematodes (Meloidogyne spp.) are the sedentary endoparasites that cause severe yield losses in chickpea. Chemical nematicides are widely used to control root–knot nematodes. These toxic chemicals pollute the soil and water environments and affect human health. The present study aimed to identify a potential bio–organic approach of management of M. javanica in chickpea. A two–year field experiment (2013–2015) was conducted to evaluate the efficacy of organic amendments (neem cake, neem seed powder and vermicompost), bio–control agent (Trichoderma harzianum), and chemical nematicides (carbofuran 3G, carbosulfan 25DS) for managing M. javanica in chickpea. The population of M. javanica in control treatment was 6.6 infective juveniles cc−1 soil. Organic amendments and bio–control agent reduced nematode population considerably in comparison to control treatment. Results showed that root galls and gall index were reduced in all the treatments over control, and the maximum reductions were observed in carbofuran 3G and neem cake treatments. Neem cake and carbofuran 3G reduced the root galls by 59% and 62% and gall index by 45% and 58% over control. Neem cake, carbofuran 3G and carbosulfan 25DS treatments resulted in the higher yield of chickpea over control treatment, which was primarily attributed to an increase in plant biomass and number of pods per plant. Chemical nematicides reduced the nodulation as compared to other treatments. Hence, neem cake could be an alternative to toxic chemical nematicides and recommended as eco–friendly management of M. javanica in chickpea. • Root-knot nematodes cause severe yield losses in chickpea. • Bio-organic products and bio-control agent suppressed the nematode infestation (M. Javanica). • Chemical nematicides affected nodulation in chickpea. • Nematicidal effect of neem cake (0.5 t ha−1) treatment was comparable to carbofuran 3G. [ABSTRACT FROM AUTHOR]