[show abstract][hide abstract] ABSTRACT: Heat is one of the major factors that considerably limit rice production. Nagina 22 (N22) is a deep-rooted, drought and heat tolerant aus rice cultivar. This study reports the characterization of a previously isolated dark green leaf mutant N22-H-dgl219 (NH219) which showed reduced accumulation of reactive oxygen species in leaf under 40[degree sign]C heat conditions.The mutant was characterized for several traits in field under ambient (38[degree sign]C) and heat stress (44[degree sign]C) conditions by raising temperature artificially from flowering stage till maturity by covering plants with polythene sheets during dry season 2011.Yield traits were mapped in 70 F2 segregants of IR64 x NH219 and 36 F2 segregants of its reciprocal cross.
Leaf proteome analysis using two-dimensional gel electrophoresis from N22 and NH219 showed distinct constitutive expression of ribulose bisphosphate carboxylase large chain precursor (EC 220.127.116.11) in NH219 under ambient growth condition. Heat stress resulted in reduction of all 11 traits except plant height in both N22 and NH219. The extent of reduction was more in N22 than in NH219. Both pollen viability and spikelet fertility were not reduced significantly in N22 and NH219 but reduced by 20% in IR64.
NH219 is more tolerant to heat stress than wild type N22 as its percent yield reduction is lesser than N22. Single marker analysis showed significant association of RM1089 with number of tillers and yield per plant, RM423 with leaf senescence, RM584 with leaf width and RM229 with yield per plant.
[show abstract][hide abstract] ABSTRACT: ABSTRACT: In Arabidopsis, non-expressor of pathogenesis related genes-1, NPR1 has been shown to be a positive regulator of the salicylic acid controlled systemic acquired resistance pathway and modulates the cross talk between SA and JA signaling. Transgenic plants expressing AtNPR1 constitutively exhibited resistance against pathogens as well as herbivory. In the present study, tobacco transgenic plants expressing AtNPR1 were studied further for their response to infection by the sedentary endoparasitic root knot nematode, Meloidogyne incognita. Transgenic plants showed enhanced resistance against the root-knot nematode infection. Prominent differences in the shoot and root weights of wild type and transgenic plants were observed post-inoculation with M. incognita. This was associated with a decrease in the number of root galls and egg masses in transgenic plants compared to WT. The transgenic plants also showed constitutive and induced expression of some PR protein genes, when challenged with M. incognita.
[show abstract][hide abstract] ABSTRACT: Infectivity of twenty nine entomopathogenic nematode (EPN) isolates belonging to the families of Heterorhabditidae and Steinernematidae
to sugarcane shoot borerChilo infuscatellus Snellen was investigated at 18 and 27°C under laboratory conditions. Although all the EPN isolates tested caused mortality
of shoot borer larvae, there were differences in the level of mortality. Among the EPN isolates tested at 27°C, 120 h after
inoculationHeterorhabditis indica (LN2),H. bacteriophora (German isolate) andSteinernema glaseri (Australian isolate) caused 100 per cent mortality of shoot borer larvae. Average time taken to kill shoot borer larvae was
least (22.8 h) in case ofH. indica (LN2) followed byS. glaseri (26.5 h) andH. bacteriophora (German isolate) (28.4 h). Mortality percentage for other isolates ranged from 39.9 to 86.6. At 18°C,S. glaseri (Australian isolate) andH. bacteriophora (German isolate) caused 100 per cent mortality 120 h after nematode inoculation; with an average time taken to kill shoot
borer larvae of 41.2 and 42.6 h respectively. All the EPN isolates took less time to cause mortality of shoot borer larvae
at 27 than at 18°C. The multiplication of EPN in shoot borer larvae infected at 27°C was comparatively more than those infected