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Genotype by environment interaction distorts genetic analysis, changes relative ranking of genotypes and a major obstruction for varietal release. AMMI model is a quick and relevant tool to judge environmental behaviour and genotypic stability in comparison to ANOVA, multiplicative model and linear regressions. We evaluated 19 barley genotypes grown at 08 diverse locations to identify discriminating environments and ideal genotypes with dynamic stability. In AMMI ANOVA, the locations and genotype by environment interaction exhibited 66% and 14.7% of the total variation. The initial first two principal components showed significant interaction with 36.0 and 28.4% variation, respectively. AMMI1 biplot showed that the environments Bawal, Ludhiana and Durgapura were high yielding with high IPCA1 scores and located far away from the biplot origin. However, in AMMI1and AMMI2 biplots the locations Hisar, Ludhiana, Karnal, Bathinda and Modipuram were found suitable with low IPCA2 scores. Yield stability index (YSI) was highly useful with ASV ranks and the genotypes DWRB150 and BH1013 and checks BH902, DWRUB52 and DWRB101 were selected for high grain yield and wider adaptability across the locations.

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The present report is in continuation to our earlier reports on the identification and fine mapping of three aroma QTLs in basmati rice using a bi-parental mapping population derived from a cross between Pusa 1121, a basmati rice variety, and Pusa 1342, a non-aromatic rice variety. We used a combination of genetic mapping and transcriptome profiling to narrow down the number of differentially expressed genes in rice to identify potential candidate genes for rice grain aroma. Highly aromatic and non-aromatic recombinant inbred lines (RILs) were identified through sensory analysis of mature milled grains. RILs with similar phenotypes were bulked together using bulk segregant analysis approach which drastically reduced the number of differentially expressed genes from 4016 to 1344. The transcriptome profiles generated were analyzed through Affymetrix rice genome array containing probe sets designed from all the predicted rice gene sequences. Microarray-based transcriptome profiling revealed one down-regulated gene co-located in QTL region aro3.1 on chromosome 3, eight genes co-located in the aro4.1 region on chromosome 4 and the badh2 gene on chromosome 8 to be differentially expressed in the aromatic parent and aromatic bulk. These genes are the most suitable candidates for future validation and development of new molecular functional markers to facilitate marker assisted breeding.

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Cereal Research Communications
Authors:
N. Sinha
,
V. Priyanka
,
K.T. Ramya
,
T. Leena
,
J.A. Bhat
,
Harikrishna
,
N. Jain
,
P.K. Singh
,
G.P. Singh
, and
K.V. Prabhu

Abiotic stresses are major constraints to wheat productivity in many parts of the world. Tolerance to abiotic stresses can be achieved indirectly by selection for morpho-physiological traits. Physiological trait based breeding has been associated with improved performance under stress; and hence can combat and adapt wheat to drought and heat stress. Therefore, in the present study, phenotyping was carried out for agro-physiological traits in 52 diverse wheat germplasm lines under timely sown, rainfed and late sown environments for two years. Mean yield of the genotypes over the six environments were positively correlated with NDVI, days to maturity and negatively correlated with canopy temperature. The phenotypic data validated marker-trait associations of a number of meta-QTLs identified earlier for different physiological and agronomic traits. Six and seven meta-QTL genomic regions were found to be consistent in their expression for two years under rainfed/restricted irrigation and late sown environments, respectively. Expression analysis of the underlying candidate gene AK248593.1 in meta-QTL26 region revealed two folds higher expression in the NILs carrying the co-localized SSR markers. The linked markers of the thirteen meta-QTL regions associated with different traits can be used for effective transfer of the QTLs through marker assisted selection in wheat breeding programmes.

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The present research endeavor was undertaken to depict the response of different generations viz., F1, F2, BC1F1, BC1F2, BC1F3, BC1F4 and BC1F5 of triticale × wheat and wheat × rye hybrids towards the different parameters of haploid induction. The experimental material included the different generations obtained utilizing five genotypes of triticale (DT-123, DT-126, TL-2900, TL-2908 and TL-9335), four genotypes of Himalayan rye (Karoki rye, shanoor rye, tino rye and triloki rye) with various elite bread wheat genotypes as parents in wide hybridization programme. The triticale × wheat and wheat × rye recombinants were further subjected to Imperata cylindrica-mediated chromosome elimination approach of doubled haploidy breeding. The variability in the haploid induction parameters was observed to be under genetic control for embryo formation and regeneration, while pseudoseed formation was only affected by auxin treatment. Among the different generations, the backcross generations viz., BC1F1 and BC1F2 were found to exhibit significant positive response towards haploid induction parameters in both triticale × wheat and wheat × rye hybridization. Knowledge of effective generation for haploid induction in triticale × wheat and wheat × rye hybridization not only saved the time and energy but also enhanced the efficiency of haploid induction.

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Cereal Research Communications
Authors:
S. Sareen
,
N. Bhusal
,
G. Singh
,
B.S. Tyagi
,
V. Tiwari
,
G.P. Singh
, and
A.K. Sarial

Heat stress is a matter of a great concern for the wheat crop. Heat stress usually either hastens crop development or shortens the grain filling duration, which severely reduces grain yield. Being a complex trait, understanding the genetics and gene interactions of stress tolerance are the two primary requirements for improving yield levels. Genetic analysis through generation mean analysis helps to find out the nature of gene actions involved in a concerned trait by providing an estimate of main gene effects (additive and dominance) along with their digenic interactions (additive × additive, additive × dominance, and dominance × dominance). In the present investigation, we elucidated the inheritance pattern of different yield contributing traits under heat stress using different cross combinations which could be helpful for selecting a suitable breeding strategy. Thus six generations of five crosses were sown normal (non-stress, TS) and late (heat stress, LS) in a randomized block design with three replications during two crop seasons. The model was not adequate for late sown conditions indicating the expression of epistatic genes under stress conditions. The traits i.e. Days to heading (DH), Days to anthesis (DA), Days to maturity (DM), Grain filling duration (GFD), Grain yield (GY), Thousand grain weight (TGW), Grain weight per spike (GWS) and Heat susceptibility index (HSI) under heat stress conditions were found under the control of additive gene action with dominance × dominance interaction, additive gene action with additive × dominance epistatic effect, dominance gene action with additive × additive interaction effect, additive and dominance gene action with dominance × dominance interaction effect, additive gene action with additive × dominance epistatic effect, additive gene action with additive × additive interaction effect and dominance gene action with additive × additive interaction effect, respectively.

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Cereal Research Communications
Authors:
N. Jain
,
G.P. Singh
,
R. Yadav
,
R. Pandey
,
P. Ramya
,
M.B. Shine
,
V.C. Pandey
,
N. Rai
,
J. Jha
, and
K.V. Prabhu

Under limiting water resources, root system response of genotypes to soil-water conditions with enhanced shoot biomass holds the key for development of improved genotypes. Based on the hypothesis of root biomass contribution to higher yields under limiting conditions which might be attributed to the root system plasticity of genotypes, a set of thirty-four genotypes were evaluated under three moisture regimes in a pot experiment for root system traits. Total root dry matter had a positive association with total shoot dry matter (0.35). The identified genotypes showed greater yields and higher stress tolerance index (STI) in an independent field experiment. Root dry matter positively correlated with stress tolerance index on grain yields in both the years. The total variation was partitioned into principal components and GGE biplots were studied to identify the best performing genotypes under the three environments for root dry biomass and related traits. HD2932 appeared to be the winner genotype under different regimes. These results might be helpful in identifying donors for moisture stress tolerance that can be utilized in wheat breeding programmes for accelerated development of varieties with improved root systems.

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Cereal Research Communications
Authors:
B. Kumar
,
K.S. Hooda
,
R. Gogoi
,
V. Kumar
,
S. Kumar
,
A. Abhishek
,
P. Bhati
,
J.C. Sekhar
,
K.R. Yathish
,
V. Singh
,
A. Das
,
G. Mukri
,
E. Varghese
,
H. Kaur
,
V. Malik
, and
O.P. Yadav

Maydis leaf blight (MLB), a serious foliar fungal disease of maize, may cause up to 40% losses in yield. The present studies were undertaken to identify the stable sources of MLB resistance, its inheritance study, and testing of MLB resistance linked markers from diverse background in the Indian adapted tropical maize genotypes. A set of 112 inbred lines were screened under artificially created epiphytotics conditions at three hotspot locations. Analysis across multi-locations revealed significant effects of genotypes and environments, and non-significant effects due to genotypes × environment interaction on disease incidence. A total of 25 inbred lines with stable resistance were identified across multi-locations. Inheritance of resistance was studied in six F1s and two F2s of resistant and susceptible parents. The null hypothesis of segregation of resistance and susceptible for mono and digenic ratios in two F2 populations was rejected by Chi-square test. The non-significant differences among the reciprocal crosses depicted the complete control of nuclear genome for MLB resistance. Partial dominance in F1s and normal distribution pattern in F2s of resistant and susceptible parents suggested polygenic nature of MLB resistance. Correlation studies in F2 populations exhibited significant negative correlation between disease score and days to flowering. Five simple sequence repeats (SSRs) markers, found associated to MLB resistance in different studies were unable to differentiate amongst MLB resistance and susceptible parents in our study. This emphasizes the need of fine mapping for MLB resistance in Indian germplasm. The identified stable sources of resistance and information on inheritance study can be used further in strengthening of resistance breeding against MLB.

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Septoria tritici blotch (STB) caused by Mycosphaerella graminicola, is one of the most destructive foliar diseases of wheat (Triticum aestivum L.) especially in temperate and humid regions across the world. The susceptibility of recently released varieties, evolution of resistance to fungicides and increasing incidence of STB disease emphasizes the need to understand the genetics of resistance to this disease and to incorporate host resistance into adapted cultivars. This study aimed to decipher the genetics and map the resistance to STB using a recombinant inbred line (RIL) mapping population derived from ‘Steele-ND’ (susceptible parent) and ‘ND 735’ (resistant parent). The RILs were evaluated in three greenhouse experiments, using a North Dakota (ND) isolate of STB pathogen. The mean disease severity of parental genotypes, ‘ND 735’ (11.96%) and ‘Steele-ND’ (66.67%) showed significant differences (p < 0.05). The population segregated for STB and the frequency distribution of RILs indicated quantitative inheritance for resistance. The mean disease severity in RILs ranged from 0 to 71.55% with a mean of 21.98%. The genome map of this population was developed using diversity array technology (DArT) and simple sequence repeat (SSR) markers. The framework linkage map of this population was developed using 469 molecular markers. This map spanned a total distance of 1,789.3 cM and consisted of 17 linkage groups. QTL mapping using phenotypic data and the framework linkage maps detected three QTL through composite interval mapping. One QTL was consistently detected in all experiments on the long arm of chromosome 5B, and explained up to 10.2% phenotypic variation. The other two QTLs, detected in single environments, were mapped to 1D and 7A and explain 13% and 5.5% of the phenotypic variation, respectively. The map position of the consistent QTL on 5BL coincides with the map position of durable resistance gene Stb1 suggesting the importance of this region of ‘ND 735’ as a source of durable STB resistance for the wheat germplasm.

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Cereal Research Communications
Authors:
S. L. Krishnamurthy
,
S. K. Sharma
,
D. K. Sharma
,
P. C. Sharma
,
Y. P. Singh
,
V. K. Mishra
,
D. Burman
,
B. Maji
,
B. K. Bandyopadhyay
,
S. Mandal
,
S. K. Sarangi
,
R. K. Gautam
,
P. K. Singh
,
K. K. Manohara
,
B. C. Marandi
,
D. P. Singh
,
G. Padmavathi
,
P. B. Vanve
,
K. D. Patil
,
S. Thirumeni
,
O. P. Verma
,
A. H. Khan
,
S. Tiwari
,
M. Shakila
,
A. M. Ismail
,
G. B. Gregorio
, and
R. K. Singh

Genotype × environment (G × E) interaction effects are of special interest for identifying the most suitable genotypes with respect to target environments, representative locations and other specific stresses. Twenty-two advanced breeding lines contributed by the national partners of the Salinity Tolerance Breeding Network (STBN) along with four checks were evaluated across 12 different salt affected sites comprising five coastal saline and seven alkaline environments in India. The study was conducted to assess the G × E interaction and stability of advanced breeding lines for yield and yield components using additive main effects and multiplicative interaction (AMMI) model. In the AMMI1 biplot, there were two mega-environments (ME) includes ME-A as CARI, KARAIKAL, TRICHY and NDUAT with winning genotype CSR 2K 262; and ME-B as KARSO, LUCKN, KARSA, GOA, CRRI, DRR, BIHAR and PANVE with winning genotypes CSR 36. Genotypes CSR 2K 262, CSR 27, NDRK 11-4, NDRK 11-3, NDRK 11-2, CSR 2K 255 and PNL 1-1-1-6-7-1 were identified as specifically adapted to favorable locations. The stability and adaptability of AMMI indicated that the best yielding genotypes were CSR 2K 262 for both coastal saline and alkaline environments and CSR 36 for alkaline environment. CARI and PANVEL were found as the most discernible environments for genotypic performance because of the greatest GE interaction. The genotype CSR 36 is specifically adapted to coastal saline environments GOA, KARSO, DRR, CRRI and BIHAR and while genotype CSR 2K 262 adapted to alkaline environments LUCKN, NDUAT, TRICH and KARAI. Use of most adapted lines could be used directly as varieties. Using them as donors for wide or specific adaptability with selection in the target environment offers the best opportunity for widening the genetic base of coastal salinity and alkalinity stress tolerance and development of adapted genotypes. Highly stable genotypes can improve the rice productivity in salt-affected areas and ensure livelihood of the resource poor farming communities.

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