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The rate of oxidation of glycine, DL-alanine, DL-valine, and DL-leucine by potassium permanganate in aqueous sulphuric and perchloric acid solution is proportional to the concentration of the amino-acid. For each amino-acid, the total order of the reaction is two at a given concentration of sulphuric and perchloric acid. The rate of oxidation of the amino-acids is greater in sulphuric than in perchloric acid for the same concentration. Various hypotheses for the mechanism of acid catalysis have been tested and it has been found that the rate is related to the activity of water in accord with Bunnett's hypothesis. There is no primary salt effect, but at higher concentrations of added neutral salts, the logarithm of the rate constant is linearly related to ionic strength. Specific ionic effects have also been found. The energy and entropy of activation and frequency factor have been calculated and a mechanism in agreement with the observations is suggested.ALTHOUGH a great deal of work has been done l-* on the kinetics and mechanism of oxidation of various organic compounds by potassium permanganate, the oxidation of amino-acids by this powerful oxidant has received little attenti~n.~-lO The present paper deals with this problem. EXPERIMENTALCrystalline glycine (Fabriques De Laire), DL-alanine (B.D.H.), DL-valine (Merck), and DL-leucine (Reanal) were used. Potassium permanganate, sulphuric acid, and chemicals other than those below were B.D.H. AnalaR products. Perchloric acid ' G R ' was supplied by Merck. Caesium sulphate was supplied by Hopkin and Williams. Doubly distilled water was used to prepare all solutions. Solutions of aniino-acids were prepared directly by weighing. Potassium permanganate solution was prepared by the method of Vogel.ll Stock solutions of sulphuric and perchloric acid were standardized against previously standardized sodium hydroxide solution. Kinetic Measuvements.-(i) Reactions were carried out in

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Chlorpyrifos (O,O'-diethyl-O-3,5,6-trichloro-2-pyridyl phosphorothionate, CPF) is a broad spectrum organophosphate pesticide used to control a variety of pests. The present study was undertaken to test the in vivo genotoxic potential of CPF in rats, using the single cell gel electrophoresis (or comet) assay. The rats were administered 50 mg and 100 mg CPF/kg body weight daily for 1, 2, and 3 days as well as 1.12 mg and 2.24 mg CPF/kg body weight for 90 days. The level of DNA damage was estimated by scoring 100 cells per animal, dividing into five types: types 0, I, II, III, and IV. The results clearly indicate that exposure to CPF, acutely or chronically, caused a dose-dependent increase in DNA damage in the liver and brain of rats. From the present study, it can be concluded that CPF exhibits genotoxic potential in vivo.

Plant breeders are interested in using diverse genotypes in hybridization that can segregate for traits of importance with possibility of selection and genetic gain. Information on molecular and agromorphological diversity helps the breeders reduce the effort for parental selection and helps the advancement of generations. A phenotypic and molecular diversity study, using 24 traits (agronomic and disease) and 6519 SNPs in a diverse collection of 336 spring barley genotypes, was carried out at Marchouch and Jemma Shiam research stations in Morocco. Based on structure and multivariate analyses, strong differentiation between the two-and six-row types were observed. The linkage disequilibrium (LD) decay of the current collection (for the combined population) was up to 3.58 cM (r 2 = 0.15) while LD decay were estimated 3.91 and 2.36 cM for two-and six-row barley, respectively. PCA of agro-morphological traits revealed grain per spike, net form of net blotch (NFNB), spot form of net blotch (SFNB), and 1000 kernel weight were the most discriminatory traits in the current collection. Association mapping in the two independent populations will be ideal for identification of markers, and QTL related to traits. The generated information on relatedness between individuals will help identify diverse genotypes for breeding programs.

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Keywords: heat stress, malondialdehyde, proline, superoxide dismutase, timely and late sown condition, wheat genotypes thermostability, canopy function, stable green habit, better mobilization rate of food reserve and other technical or physiological parameters might be helpful to overcome yield loss under terminal heat stress. 12 In vitro studies of wheat plants in combination with genetic manipulation to develop heat tolerant wheat are of limited success. Therefore, the complex physiological-genetic approach could be useful to acquire heat tolerance in wheat to minimize the farmer's risk for reduced yield and low quality grain product. Here, Physiological evaluation of wheat genotypes was performed under timely and late sown condition. Results Estimation of chlorophyll index (SPAD-values), leaf area index (LAI) and proline content. Chlorophyll content (SPAD-values)of wheat genotypes viz., DBW-140, RAJ-3765, PBW-574, K-0-307 and HS-240 under timely and late sown was calculated after 30, 50, 70, 90 and 110 d. It was found that SPAD-values affected under timely and late sown conditions were 41.5, 38.9, 37.08, 37.67, 47.7, 47.59, 46.56, 46.73, 41.03, 40 and 40.15, 34.5, 34.76, 33.33, 45.63, 44, 43.03, 42.52, 4,137 and HS-240 genotypes showed highest reduction in LAI (0.3, 1.36, 3.78, 3.0 and 0.37, 2.08, 3.94, 3.29) at 30, 70 and 90 d after sowing, respectively (Fig. 1B). The proline content (μg g −1 FW) was found to be increased in all the genotypes studied (30.25, 160.5, 135.2, 262.1, 184.0 and 221.68, 236.55, 261.77, 419.35) under late sown condition as compared with that of timely sown condition (89.6, 106.8, 119.6, 62.0 and 21.98, 20.66, 37.0, 20.86, 18.37) at both anthesis and 15 DAS, except , respectively (Fig. 1C).Evaluation of malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, heat susceptibility index (s) (HIS) and yield associated traits. The amount of malondialdehyde (MDA) (μ mole g −1 FW) produced when polyunsaturated fatty acids in the membrane undergone lipid peroxidation in wheat genotypes were calculated as 13. 06, 11.80 and 7.26, 4.23 in HS 240 and K-0-307 genotypes respectively at the time of anthesis in late sown and timely sown conditions. The similar trends were also observed in HS 240 and K-0-307 genotypes 15 DAS, which followed by Raj 3765, DBW 140 and PBW 574 genotypes ( Fig. 2A). There is no significant increase in superoxide dismutase (SOD) activity (unit mg −1 FW) in genotypes evaluated at anthesis stage under timely and late sown conditions. In contrast, after 15 d of anthesis SOD activity was highest in RAJ-3765 (1.88) whereas in HS-240 and K-0-307 genotypes it was lowest (1.63 and 1.60) under late sown condition (Fig. 2B). The heat susceptibility index (HIS) of HS 240 and K-0-307 wheat genotypes was highest (1.33, 1.57, 1.51 and 1.17, 1.34, 1.65), which followed by DBW 140, Raj 3765 and PBW 574 genotypes (0.846, 0.649 and 0.411), (0.780, 0.905 and 0.905) and (0.897, 0.457 abd 0.682) for 1000-grain weight, grain weight and grain yield, respectively (Fig. 2C). Y...