Authors:C. V. Chaudhari, Y. K. Bhardwaj, and S. Sabharwal
Grafting ofmethyl methacrylate (MMA) on radiation crosslinked natural rubber (NR) film has been investigated by mutual radiation
grafting. The effect of experimental parameters like radiation dose, dose-rate, additives like acids and inorganic salts,
solvents, monomer concentration, cross-linking density of the natural rubber film on the grafting extent has been studied.From
the kinetic studies, a kinetic equation showing almost parabolic and linear dependence of grafting on concentration and dose
rate, respectively, was deduced.Preliminary thermal stability studies of grafted films indicated that grafting of MMA does
not enhance the thermal stability of NR.
Authors:S. Bhardwaj, M. Prashar, S. Jain, S. Kumar, Y. Sharma, M. Sivasamy, and I. Kalappanavar
Two new pathotypes of
, 121R60-1 and 377R60-1 the latter virulent on
, are described for the first time. Both the pathotypes are designated as MHTTS as per North American system of pathotype identification. Pathotype 377R60-1 appears to be the result of a single step mutation for virulence to
in pathotype 121R60-1. Both pathotypes appear closely related to the most prevalent virulent pathotype 121R63-1(THTTS). The avirulence/virulence profile, resistance sources and their possible relationship with other pathotypes are discussed.
is now included as one of the differentials for the identification of leaf rust pathotypes.
Authors:C. Chaudhari, K. Dubey, Y. Bhardwaj, Virendra Kumar, N. Goel, and S. Sabharwal
Radiation induced grafting of acrylonitrile (ACN) on ethylene-propene diene terpolymer (EPDM) rubber film was investigated
by mutual radiation grafting technique. Effect of experimental variables viz. radiation dose, dose rate, type of solvent and
monomer content on extent of grafting was studied. From the kinetic studies a mathematical relation Rgα[M]0.7D0.68 showing non-linear relationship for rate of grafting with monomer concentration and dose was deduced. The grafted samples
showed increased hardness and oil resistance.
Authors:H. Khan, S.C. Bhardwaj, O.P. Gangwar, P. Prasad, P.L. Kashyap, S. Savadi, S. Kumar, and R. Rathore
A set of forty wheat cultivars comprising bread wheat, durum and triticale identified during 2010–2014 were tested for resistance to Indian pathotypes of leaf, stem and yellow rusts at seedling stage under controlled conditions. Eight Lr genes (Lr1, Lr3, Lr10, Lr13, Lr14a, Lr23, Lr24 and Lr26) were characterized based on differential interactions with specific rust races. Genes Lr23, Lr26 and Lr13 conferred leaf rust resistance in most of the accessions. Three Yr genes (YrA, Yr2 and Yr9) were inferred in 40 genotypes, where Yr2 followed by Yr9 were most frequent in conferring stripe rust resistance. Ten Sr genes, namely, Sr2, Sr5, Sr8a, Sr7b, Sr9b, Sr9e, Sr11, Sr13, Sr24 and Sr31, were postulated in these lines with predominance of Sr11, Sr31 and Sr2. These Lr, Sr and Yr genes were observed singly or in combination. Robust DNA markers were used to identify adult plant resistance genes Yr18/Lr34/Sr57, Lr68 and Sr2 and all stage resistance genes Lr24/Sr24, Sr28 and Yr9/Lr26/Sr31. STS marker iag95 showed presence of Yr9 in four additional cultivars which were resistant to one or more rusts. Gene Sr28 was identified in seven durum cultivars with the wPt7004 marker. This is first report of Sr28 being present in many Indian wheat cultivars. CsGs-STS marker identified Lr68 in nine cultivars.