Raj Kumar Gupta

Saline-water irrigation for the establishment of furrow-planted trees in northwestern India

Appropriate tree species and planting methods can help rehabilitation of arid areas — that are characterized by low rainfall, high evapotranspiration demands, highly saline ground waters and calcareous subsoils. The growth of Acacia nilotica and Dalbergia sissoo saplings planted in irrigation furrows in such an arid zone of northwest India was not affected adversely by irrigation with saline water of EC W 10.5 dS m−1. The growth of A. nilotica, measured in terms of sapling survival, plant height and biomass yields, was better than that of D. sissoo. Increasing the period of irrigation from the recommended practice of irrigating only in the first year dry season (October–June) to second and third dry seasons (years) improved the sapling survival, growth and biomass (two-to-three-fold) and water use efficiency (two-to-four fold). Most of the salts added with saline irrigation were accumulated below the irrigation channels and were pushed laterally during the monsoon season. The results indicate that the furrow planting technique could be adopted as an afforestation practice in view of the creation of favourable water and salt regimes and their impact on the establishment of trees saplings. Irrigation water supplies for a minimum of intitially two years after transplanting seemed necessary.

Antioxidant activity and phenolic content of the Indian wheat varieties

In this study, Indian wheat varieties grown under different agro-climatic zones were evaluated for their antioxidant potential. Different grain fractions (bran, flour, shorts) and the whole meal were tested using two free radicals (ABTS and DPPH) for their radical scavenging activities. More variation was observed in the antioxidant activities from different zones using DPPH assay. Irrespective of the method used, the whole meal and the bran of central zone varieties showed the highest and the north western plains zone varieties showed the lowest antioxidant activities. Within each growing zone, both the effect of genotype and environment was observed on the antioxidant activity. Both free and bound phenolic compounds were extracted from the bran of varieties representing different zones. Total phenolic content (TPC) varied from 2,900 to 5,650xa0μg Gallic acid equivalents/g of bran. Bound phenolic content was found to be more strongly correlated to the TPC than the free phenolic content. Highly significant genotypic differences were observed in the total phenolic content. This study therefore indicates that Indian wheat varieties have good antioxidant activity and high content of phenolic compounds and can be used further in breeding programmes to increase the content of phytochemicals responsible for antioxidant activity.

Chromosome Specific Substitution Lines of Aegilops geniculata Alter Parameters of Bread Making Quality of Wheat

Wheat cultivars with wide introgression have strongly impacted global wheat production. Aegilops geniculata (MgUg) is an important wild relative with several useful traits that can be exploited for wheat improvement. Screening of Ae. geniculata addition lines indicated a negative effect of 1Ug and the positive effect of 1Mg chromosome on wheat dough strength. Negative effect of 1Ug is probably associated with variation in number and position of the tripeptide repeat motif in the high molecular weight glutenin (HMW-G) gene. To utilize the positive potential of 1Mg chromosome, three disomic substitution lines (DSLs) 1Mg(1A), 1Mg(1B) and 1Mg(1D) were created. These lines were characterized for morphological, cytogenetic properties and biochemical signatures using FISH, 1D-, 2D-PAGE and RP-HPLC. Contribution of wheat 1A, 1B and 1D chromosomes towards dough mixing and baking parameters, chapatti quality, Fe/Zn content and glume color were identified. Observed order of variation in the dough mixing and baking parameters {1Mg(1D) ≤wheat ≤1Mg(1B) ≤1Mg(1A)} indicated that chromosome specific introgression is desirable for best utilization of wild species’ potential.

Relevance of physiological efficiency in wheat grain quality and the prospects of improvement

Released and pre-released bread wheat varieties evaluated in national wheat programme of India (503 genotypes) during 2005–14 under different environments were examined for the role of physiological parameters in grain quality. Genotypes with slow plant height growth but faster rate of grain filling enhanced protein content. Plants where growth in height and grain development was slow, grains were hard, provided proportionate vegetative growth phase is longer. Steady grain growth rate benefited gluten strength and gluten quality. Irrespective of total crop duration, longer reproductive phase was an effective indicator of higher flour recovery and test weight. Magnitude and significance of morphological attributes in grain quality was almost similar to that of physiological processes, therefore prospects of utilizing these field traits were examined to enhance grain properties. Early heading and longer grain filling was effective to increase test weight whereas delayed heading and shorter plant height enhanced protein content. Bold grains hampered grain hardness and delayed heading added more bran in the flour. Genotypes with poor grain bearing and quick grain ripening had lower sedimentation value. Instead of protein, it was wet gluten which expressed negative association with yield. To improvise gluten quality, extended reproductive phase but with less grain weight was helpful. Contribution of longer post-anthesis period was observed crucial in flour recovery. These useful simple field expressions can be deployed to uplift quality of wheat grains.

Rapid Development and Characterization of Chromosome Specific Translocation Line of Thinopyrum elongatum with Improved Dough Strength

The protein content and its type are principal factors affecting wheat (Triticum aestivum) end product quality. Among the wheat proteins, glutenin proteins, especially, high molecular weight glutenin subunits (HMW-GS) are major determinants of processing quality. Wheat and its primary gene pool have limited variation in terms of HMW-GS alleles. Wild relatives of wheat are an important source of genetic variation. For improvement of wheat processing quality its wild relative Thinopyrum elongatum with significant potential was utilized. An attempt was made to replace Th. elongatum chromosome long arm (1EL) carrying HMW-GS genes related to high dough strength with chromosome 1AL of wheat with least or negative effect on dough strength while retaining the chromosomes 1DL and 1BL with a positive effect on bread making quality. To create chromosome specific translocation line [1EL(1AS)], double monosomic of chromosomes 1E and 1A were created and further crossed with different cultivars and homoeologous pairing suppressor mutant line PhI. The primary selection was based upon glutenin and gliadin protein profiles, followed by sequential genomic in situ hybridization (GISH) and fluorescent in situ hybridization (FISH). These steps significantly reduced time, efforts, and economic cost in the generation of translocation line. In order to assess the effect of translocation on wheat quality, background recovery was carried out by backcrossing with recurrent parent for several generations and then selfing while selecting in each generation. Good recovery of parent background indicated the development of almost near isogenic line (NIL). Morphologically also translocation line was similar to recipient cultivar N61 that was further confirmed by seed storage protein profiles, RP-HPLC and scanning electron microscopy. The processing quality characteristics of translocation line (BC4F6) indicated significant improvement in the gluten performance index (GPI), dough mixing properties, dough strength, and extensibility. Our work aims to address the challenge of limited genetic diversity especially at chromosome 1A HMW-GS locus. We report successful development of chromosome 1A specific translocation line of Th. elongatum in wheat with improved dough strength.

An Analysis to Explore Divergence of HMW Glutenin Subunits in High-Yield Indian Wheat of Different Production Environments

Fifteen years grain quality data of 231 high yielding bread wheat genotypes evaluated in different production environments of India was examined to understand prevalence of high molecular weight glutenin subunits (HMWGS) in different production environments. Six agro-climatically diverse zones and two production conditions (timely-sown and late-sown) per zone represented diverse wheat growth environments prevailing in India. Difference in frequency level of different subunits has been explained in this review. Accurance of various subunits varied promptly in diffrenrent zones (Glu B1) and climates (Glu D1). Diffrence as per production condition was also noticed in same variants of Glu B1 locus. Parallelism between quality of bread and the glutenin subunits was observed under varying wheat growth environments. It was further demonstrated that overall product quality of a given production environment can be better explained by ratio between desirable and undesirable HMW glutenin subunits.

Gluten characteristics imparting bread quality in wheats differing for high molecular weight glutenin subunits at Glu D1 locus

High yielding genotypes differing for high molecular weight glutenin subunits at Glu D1 locus in national wheat programme of India were examined for bread loaf volume, gluten and protein contents, gluten strength, gluten index and protein-gluten ratio. Number of superior bread quality genotypes in four agro-climatically diverse zones of Indian plains was comparable in both categories of wheat i.e., 5u2009+u200910 and 2u2009+u200912. There wasn’t any difference in average bread loaf volume and grain protein content either. 5u2009+u200910 wheats showed better gluten strength and their gluten quality was also superior in the zones where protein content was high. 2u2009+u200910 wheats exerted more gluten due to better protein-gluten ratio. Good bread making in 5u2009+u200910 was derived by better gluten strength and also gluten quality in certain regions but bread quality in 2u2009+u200912 wheats was channelized through higher gluten content as they were more efficient in extracting gluten from per unit protein. Difference in route to bread quality was apparent as gluten content and gluten strength were the key gluten attributes in 5u2009+u200910 whereas protein content and gluten index were prominent in 2u2009+u200912 types. Unlike 2u2009+u200912, there was a ceiling in gluten harvest of 5u2009+u200910 wheats as higher protein failed to deliver more gluten after some limit.