A functional canonical WNT signaling pathway exists in preimplantation embryos and inhibits embryonic development. Recent studies suggest that this pathway is over-expressed in nuclear transferred (NT), compared to IVF embryos. The present study investigated the effects of Dickkopf-1 (DKK1), an inhibitor of canonical WNT signaling pathway and colony stimulating factor-2 (CSF2), an embryokine, on the developmental competence, quality, gene expression and live birth rate of NT buffalo embryos produced by Hand-made cloning (HMC). Following supplementation of the in vitro culture medium on day 5 with DKK1 (100 ng/mL), CSF2 (10 ng/mL), DKK1+CSF2 or no supplementation (control), the blastocyst rate was higher (P < 0.05) with DKK1 and DKK1+CSF2 (42.6 ± 1.4% and 46.6 ± 0.9%, respectively) than with CSF2 or controls (40.6 ± 1.3% and 39.0 ± 1.3%, respectively). The apoptotic index of the blastocysts was lower (P < 0.05) for DKK1, CSF2 and DKK1+CSF2 groups (3.44 ± 0.14, 3.39 ± 0.11 and 3.11 ± 0.22, respectively) compared to controls (6.64 ± 0.25), and was similar to that of the IVF blastocysts (3.67 ± 0.18). Although the total cell number was similar for the DKK1, CSF2, DKK1+CSF2 and control groups (200.4 ± 3.05, 196.4 ± 3.73, 204.7 ± 3.71 and 205 ± 4.03, respectively), the inner cell mass:trophectoderm cell number ratio of DKK1, CSF2 and DKK1+CSF2 groups (0.21 ± 0.01, 0.17 ± 0.01 and 0.22 ± 0.02, respectively) was higher (P < 0.05) than controls (0.13 ± 0.01) and was similar to that of IVF blastocysts (0.19 ± 0.01). Treatment with DKK1 or CSF2 or both increased (P < 0.05) the expression level of OCT4, NANOG,SOX2, GATA6, BCL2, PTEN, P53, FGF4, GLUT1 and IFN-τ, and decreased that of C-MYC, CDX2, CASPASE, DNMT3a, TCF7 and LEF1 in blastocysts, compared to controls. Transfer of DKK1-treated embryos to 13 recipients resulted in 4 pregnancies (30.8%; 2 live births, one abortion and one currently at 9 months of pregnancy) whereas, transfer of DKK1+CSF2-treated embryos to 16 recipients, resulted in 4 pregnancies (25.0%), all of which resulted in live births. No pregnancy was obtained after transfer of control and CSF-treated embryos to 12 and 16 recipients, respectively. These results suggest that DKK1 treatment of NT embryos increases the blastocyst, conception and live birth rate, and improves their quality whereas, CSF2 treatment, does not affect the blastocyst, conception and live birth rate despite improvement in embryo quality.

Combining ability for yield and its related traits was studied in 13 barley genotypes and their F1 progenies obtained through line x tester mating design. Significant differences for most of the traits in both gca and sca components revealed the importance of both additive and non-additive gene actions with the predominant effect of nonadditive gene action. Among parents, lines DWRB 134, BH 902 and RD2919 emerged as good general combiner for yield and importantcomponent traits whereas DWRUB 52 was identified as the best tester. Hence, these are considered as good general combiners for deriving desirable transgressive segregants for specific characters. However, line BH 902 emerged as good general combiner for maximum number of yield contributing traits i.e., peduncle length, spike length, awn length, productive tillers per plant, flag leaf area, number of grains per spike, weight of spike, 1000 grain weight, biological yield per plant and grain yield per plant. Among thirty crosses, seven displayed significant and positive specific combining ability (sca) effects for grain yield. Out of these seven crosses, four hybrids viz., BH 976 × RD 2849, DWRB 134 × DWRUB 52, BH 965 × DWRUB 52, BH 902 ×DWRB 101, were identified as the best promising combinations having good specific combining ability effects along with high per se performance for grain yield as well as other attributing characters in desired direction. The estimates of general combining ability (gca) effects as a whole suggested that if most of the characters are to be improved, inclusion of F1 hybrids showing high sca in crop improvement program and parents with good gca, into multiple crosses, bi-parental mating, and diallel selective mating could prove a worthwhile approach for tangible advancementof grain yield in barley. Doi.org/10.25174/2249-4065/2018/83148

Combining ability for yield, its contributing traits and heat tolerance traits was studied in 17 parental genotypes (14 lines, 3 testers) in a line x tester scheme in timely and late sown condition and pooled environment. The purpose of the study was to identify and select superior parents and best hybrid combinations on the basis of general and specific combining abilities. The differences among genotypes were highly significant for all the characters studied. Estimates of variance due to general combining ability (gca) and specific combining ability (sca) and their ratio revealed that both additive and non-additive gene effects were important for different characters studied. The estimates of gca effects as a whole suggested that most of the traits are to be improved through hybridization and selection, the priority should be given to parents BAV 92 in timely sown condition, VL 944 in late sown condition and PBW 644 in pooled condition among the lines. PBW65*/PASTOR x DPW 621-50 was the best specific cross in timely sown condition, BAV 92 x UP 2572 in late sown condition and HD 2888 x DPW 621-50 in pooled condition for most of the traits.

Constant or transitory high temperatures affect plant growth and development inducing diverse morphological and physiological changes in plants which ultimately causes yield decrease. The traits like relative injury (RI%), chlorophyll content, canopy temperature depression (CTD), heat susceptibility index (HSI), 1000-kernel weight (TKW), grain filling duration (GFD) were used in present study to assess the capability of plants to tolerate heat stress. The study revealed that the evaluated wheat genotypes showed variable degree of tolerance against heat for different traits. On the basis of morpho-physiological traits such as RI, chlorophyll content at 15 days after anthesis (DAA), CTD at 15 DAA, HSI, TKW, GFD, genotypes HD2329 x HD2967 (19.2%), WH1021 (-21.7%), JOB666 X WH1105 (-37.5%), WH1124 X HD2967 (0.55), HD2891 (2.1%) and WAXWING X HD2967 (-2.15%) were identified as the most heat tolerant genotypes for respective characters. For grain yield out of 54 wheat genotypes, DBW90, HD2329, UP2843 x HD2967, WH1124 x HD3059, WH1124 x HD2967, MACS6272 x WH1105, MACS6272 x HD2967, HD2891 x WH1105 and UP2338 were classified as heat tolerant.

Reaction of Neovossia indica in bread wheat, with particular reference to the role of resistance in minimizing its infection and quantitative loss caused by it, were observed with virulent isolate of Neovossia indica in a set of population. Whole set of population consisted of resistant parents (HD 29, Lok 1 and Raj 3777), susceptible parents (WL 711, UP 262 and UP 2425), F1, F2 and backcross (BC1 and BC2) generations. F1 was derived from crossing between resistant and susceptible parents in half diallel fashion. Maximum percent infection i.e., 17.9% was recorded in the susceptible parent i.e, WL 711, which resulted in 4.65 % (maximum) grain yield loss, while only 0.86 % (minimum) infection resulted in 0.22% grain yield loss was recorded in the back cross generation of the cross Raj 3777/ Lok-1 (resistant x resistant). However, overall 6.0 % percent infection and grain yield loss 1.49% was recorded by all generations. The present study reveals good scope for resistance breeding in minimizing the percent infection and ultimately yield loss due to infection of Karnal bunt.

Karnal bunt is a potential threat to international trade of commercial grain and wheat germplasm, as importing countries insist on zero tolerance level. All the F1 progenies showed resistant type of response towards Karnal bunt; however, segregation in the F2 generations revealed that resistant parents had a different set of genes conferring Karnal bunt resistance. Two crosses namely, HD-29/HP-1531 and WH-485/HD-29 segregated in the pattern of 13 (resistant): 3 (susceptible) indicating that resistance to karnal bunt is controlled by two dominant genes and the genes interacted with each other in dominant recessive manner. On the other hand, WH-485/HP-1531 gave a ratio of 15:1 (resistant/susceptible) indicating the duplicate dominant type of gene action. BC2 populations segregated in 3:1 (resistant/susceptible) ratio, which again confirmed the results of F2 generations.

An experiment was conducted to determine the nature and number of genes for resistance to spot blotch (Bipolaris sorokiniana) in three genotypes of wheat (Triticum aestivum L.) Viz., PBW 343, PBW 373 and WH 581. Evaluation of all parents i.e., parent I (P-1), parent 2 (P-2), and the four generations viz., first filial generation (F-1), second filial generation F-2, backcross generation 1 (BC1) and backcross generation 2 (BC2) of these nine crosses was carried out under artificial epiphytotic conditions in the field. The F-1 hybrids between resistant and susceptible parents, namely, UP 2338, PBW 154 and Sonalika were resistant to spot blotch. Appearance of resistance in F1 indicated that resistance is dominant over susceptibility. The F-2 population derived from seven of these nine crosses segregated in a ratio of 15:1 (resistant: susceptible) for spot blotch reaction showing that resistance is conditioned by two dominant genes with duplicate gene interaction. On the other hand, 9:7 (resistant/susceptible) ratio in F-2 populations of two crosses (UP 2338 x WH 581 and Sonalika x WH 581) indicated complementary gene interaction. The backcross progenies with susceptible parents in each cross segregated into 3 resistant: 1 susceptible as expected further confirming the hypothesis.

Bipolaris sorokiniana, a causal agent of spot blotch has become a serious disease constraints for wheat cropping in the warmer and humid growing regions of the world, including India, Bangladesh, tarai of Nepal and Brazil (3,11,12) due to the high temperature and humidity at the late growth stage in these areas. However, its importance has increased recently (18,2) as the production of wheat has expanded into newer growing area. The average yield loss due to spot blotch in south Asia and India has been estimated to be 19.6 and 15.5%, respectively (3). Yield losses between 7.63 and 36.66 % have been reported by Goel et al. (7) and losses up to 100% may occur under the most severe conditions on infection (13).

Spot blotch caused by Bipolaris sorokiniana is gaining importance especially in North Western and North Eastern Plain Zones (NWPZ and NEPZ) of India. The experiment was conducted at Crop Research Centre, Pantnagar in Tarai region of Uttaranchal by taking three resistant i. e. WH 581, PBW 343 and PBW 373, three susceptible varieties, UP 2338, PBW 154 and Sonalika, and their F" F2, B, and B2 generations. The average yield and 1000-grain weight losses due to spot blotch were 17.63 and 19.35 per cent, respectively in different generations. The grain yield loss ranged from 7.63 to 36.66 per cent while reduction in 1000- grain weight ranged from 7.07 to 43.65 per cent. The resistance genotype(s) exhibited minimum loss in comparison to the susceptible genotype(s).

One hundred seventy three wheat genotypes of Indian and exotic origin were studied for genetic divergence. Out of 14 quantitative traits studied, six traits viz. biological yield/plant. grain yield/plant, number of tillers/plant, grain weight/spike, flag leaf area and harvest index exhibited high variability. Moderate level of variability was exhibited by three traits viz., spike length excluding awns, number of grains/spike and 100 grain weight. Relatively low variability was observed for flag leaf sheath length, spike length including awns, peduncle length, plant height and number of spikelets/spike. Non hierarchical Euclidean cluster analysis grouped the 173 genotypes into 15 non-overlapping clusters, the cluster IV being the largest with 27 genotypes while cluster XIII consisted of only one genotype. No relationship between geographical and genetical diversity was revealed. On the basis of mean performances of the genotypes within the clusters, 12 genetically divergent genotypes were selected, that can be involved in hybridization programme for the improvement of yield.