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Corrosion characteristics of some commercially pure aluminum alloys (1060, 1100, 3003, and 5052) in different concentrations of nitric acid have been studied at different temperatures. Alloy 3003 exhibits maximum corrosion in all the acid concentrations followed by 5052, 1100, and 1060 alloys. The corrosion rate of aluminum is found to increase and decrease with time in 20 and 70% acid solutions, respectively. In the concentration range of 20-50% of the acid, all the alloys exhibited slightly passivating tendency during the potentiostatic anodic polarization. The breakdown potential Eh of the alloys varies inversely with temperature, whereas an invariable enobling in steady-state corrosion potential with rise in temperature is noted. The current density required for initiation of passivation, i.e. Ic is related to temperature T by logI,.= a + bT where a and b are constants. The alloys exhibited negative steady-state corrosion potentials in a concentration range of 1-58% of the acid, but above this concentration positive values of the potentials have been noted. Variation of corrosion rates of the different alloys in different concentrations of the acid has been discussed in the light of the presence of different alloying elements. The influence of the addition of 0.025M, 0.05M, 0.1M, 0.25M, and 0.5M chloride, bromide, iodide, acetate, citrate, sulfate, and nitrate as their sodium salts has also been investigated on the anodic dissolution of 1060 alloy in 20% nitric acid. At concentrations of 0.025M, 0.05M, and 0.1M, CI-, Br-. and I-have little noticeable effect, but at concentrations of 0.25M and 0.5M of the former two compounds very fast corrosion was recorded and the last compound appeared to be a corrosion inhibitor. The tolerable concentration of chloride ion increases with increase in the concentration of nitric acid in conformity with log Ca~ = a + b log Cp~ Acetate, citrate, sulfate, and nitrate ions inhibit the dissolution of the alloy at all the concentrations used. It has been concluded that the sodium ion does not affect the dissolution tendency of the alloy and the anions are solely responsible for inhibiting the dissolution of the metal.

Inheritance of resistance to Fusarium wilt (FW) disease caused by Fusarium udum was investigated in pigeonpea using four different long duration FW resistant genotypes viz., BDN-2004-1, BDN-2001-9, BWR-133 and IPA-234. Based on the F2 segregation pattern, FW resistance has been reported to be governed by one dominant gene in BDN-2004-1 and BDN-2001-9, two duplicate dominant genes in BWR-133 and two dominant complimentary genes in resistance source IPA-234. Further, the efficacy of six simple sequence repeat (SSR) markers namely, ASSR-1, ASSR-23, ASSR-148, ASSR-229, ASSR-363 and ASSR-366 reported to be associated with FW resistance were also tested and concluded that markers ASSR-1, ASSR-23, ASSR-148 will be used for screening of parental genotypes in pigeonpea FW resistance breeding programs. The information on genetics of FW resistance generated from this study would be used, to introgress FW resistance into susceptible but highly adopted cultivars through marker-assisted backcross breeding and in conventional breeding programs.

Rice is the most important food crop both in value and volume for the Asian population. Frequent drought, flood and salinity stresses exacerbated by global climate change adversely affect rice production in more than fifty percent of the rice growing areas. Green revolution high yielding varieties carrying sd1 dwarfing gene have almost fully replaced the traditional climate resilient landraces and varieties of rice. However, these were bred primarily for yield under high input conditions and therefore are sensitive to adverse climatic conditions. Hence, there is urgent need to combine the high productivity with climate resilience. Knowledge of rice genome and genes for tolerance to different abiotic stresses provided us an opportunity to transfer favorable alleles of these genes into high yielding varieties through genomics-assisted backcross breeding through multi-institutional networks. Six consistent genomic regions (QTLs) for grain yield under drought; namely qDTY1.1, qDTY2.1, qDTY2.2, qDTY3.1, qDTY3.2 and qDTY12.1 have been transferred to flood tolerant versions of mega varieties of rice, Swarna, Samba Mahsuri and IR 64. To address the problem of flash flooding qSUB1 QTL has been transferred to nine popular rice varieties, namely ADT 46, Bahadur, Ranjit, HUR 105, Sarjoo 52, Pooja, Pratikshya MTU 1075 and Rajendra Mahsuri. Further, qSALTOL1 QTL for seedling stage salt tolerance and qSSISFH8.1 for reproductive stage salt tolerance have been transferred to six popular rice varieties, ADT 45, Gayatri, MTU 1010, PR 114, Pusa 44 and Sarjoo 52. We used foreground selection markers for the presence of desired gene/QTL and recombinant selection markers for reduction of linkage drag around these genes. Genotypic background selection was done after BC3F3 stage using a 50K SNP chip on a set of 20 advance lines obtained by phenotypic selection for closeness to the recipient parents. Near-isogenic lines (NILs) with more than 95% similarity to the recipient parent genome have been released and notified for commercial cultivation and are gaining fast popularity. These climate smart rice varieties will provide production stability in the adverse ecologies and support farmer’s income and livelihood.

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