IntroductionThe case of combined drought and salinity stress is increasingly becoming a constrain... more IntroductionThe case of combined drought and salinity stress is increasingly becoming a constraint to rice production, especially in coastal areas and river deltas where low rainfall not only reduces soil moisture levels but also reduces the flow of river water, resulting in intrusion of saline sea-water. A standardized screening method is needed in order to systematically evaluate rice cultivars under combined drought+salinity at the same time because sequential stress of salinity followed by drought or vice-versa is not similar to simultaneous stress effects. Therefore, we aimed to develop a screening protocol for combined drought+salinity stress applied to soil-grown plants at seedling stage.MethodsThe study system used 30-L soil-filled boxes, which allowed a comparison of plant growth under control conditions, individual drought and salinity stress, as well as combined drought+salinity. A set of salinity tolerant and drought tolerant cultivars were tested, together with several ...
DRR Dhan 57 [IET 26171 (RP 5601-283-14-4-1)], an aerobic rice variety was developed from BPT5204/... more DRR Dhan 57 [IET 26171 (RP 5601-283-14-4-1)], an aerobic rice variety was developed from BPT5204/ Azucena cross combination. It was evaluated in AICRIP multi-location aerobic rice trials during the wet seasons of 2016 to 2020. DRR Dhan 57 consistently outperformed the check varieties in Eastern Zone (Zone III) and Central Zone (Zone V) with a mean grain yield of 4782 kg/ha, which is 13%, 17% and 16 % higher than the National, Zonal and Local checks, respectively. In addition, it exhibited moderate resistance to leaf blast and Neck blast; and to gall midge and rice thrips, and moderate resistance to planthoppers and whorl maggot. DRR Dhan 57 has a mid-early duration of 120 days (seed to seed) and possesses desirable grain and cooking quality parameters. It was released for cultivation in aerobic ecosystems of Jharkhand (Zone III), and Chhattisgarh (Zone V) states through Central Sub-committee on Crop Standards, Notification and Release of Varieties for Agricultural Crops; vide S.O. 8...
Journal of Agricultural Science and Technology, 2015
Pasting is one of the most important properties of wheat starch determining the flour quality and... more Pasting is one of the most important properties of wheat starch determining the flour quality and functionality. Twenty three New Plant Type (NPT) wheat derivatives along with three checks (PBW 343, HD 2329, and Raj 3765) have been studied in multi-location trials to assess the variation and environment induced fluctuations for their starch pasting properties. Although all flour pasting characteristics varied, Breakdown Viscosity (BV) and Setback Viscosity (SV) exhibited greater variability across environments. Additive Main effects and Multiplicative Interaction (AMMI) analysis indicated significant interactions between Genotypes and Environments Interaction (GEI) in starch pasting properties. Genotypes accounted largest proportion (39.78%) of the Sum of squares (SQ) for peak viscosity (PV) followed by environments (33.30%) and GEI (33.30%). Trough Viscosity (TV), GEI accounted for the largest proportion (40.44%) of the SQ followed by environments (31.76%) and genotypes (27.80%). G...
Genetic diversity was assessed among 40 wheat genotypes consisting of new plant type (NPT) wheat ... more Genetic diversity was assessed among 40 wheat genotypes consisting of new plant type (NPT) wheat derivatives, advanced breeding lines and released varieties since 1905 using 40 STMS markers. The total number of alleles amplified by 40 STMS markers was 113. The number of alleles amplified per STMS marker varied from one to six with an average of 3.32 alleles among the polymorphic markers. More alleles were detected for the B (3.55) genome derived STMS markers than A (3.18) and D (2.75) genomes. The maximum polymorphic information content (PIC) of 0.63 with an average of 0.35 was recorded while the PIC values for A, B, and D genomes were 0.243, 0.288 and 0.339 respectively. We identified 12 informative markers with three to six alleles and average of four alleles per marker and PIC values ranged from 0.31 to 0.63. Pair wise similarity coefficients ranged from 0.22 to 0.77 suggesting wider genetic diversity among wheat genotypes. The advanced breeding lines and NPT wheat derivatives exhibited different levels of diversity as compared with released cultivars since 1905 which could be utilized in widening the genetic base of wheat and as parental lines to tag as well as to mobilize useful traits for genetic improvement of wheat
Bacterial blight (BB) disease reduces the yield of rice varieties and hybrids considerably in man... more Bacterial blight (BB) disease reduces the yield of rice varieties and hybrids considerably in many tropical rice growing countries like India. The present study highlights the development of durable BB resistance into the background of an elite maintainer of rice, DRR17B, by incorporating two major dominant genes, Xa21 and Xa33 through marker-assisted backcross breeding (MABB). Through two sets of backcrosses, the two BB resistance genes were transferred separately to DRR17B. In this process, at each stage of backcrossing, foreground selection was carried out for the target resistance genes and for non-fertility restorer alleles concerning the major fertility restorer genes Rf3 and Rf4, using gene-specific PCR-based markers, while background selection was done using a set of 61 and 64 parental polymorphic SSR markers respectively. Backcross derived lines possessing either Xa21 or Xa33 along with maximum genome recovery of DRR17B were identified at BC3F1 generation and selfed to deve...
Rice (Oryzasativa.L.) is the staple food for more than half of the world population. Over 3 billi... more Rice (Oryzasativa.L.) is the staple food for more than half of the world population. Over 3 billion people in Asia alone derive 80% of their energy needs from rice. In addition to yield enhancement, quality improvement has now become the primary consideration in breeding programmes. Rice is the only cereal that is eaten as whole grain and human selection down the ages has given high preference to quality to cater to the needs of diverse rice based preparations. Grain quality in rice is difficult to define with precision as preference for quality varies from country to country and within the country from region to region and between ethnic groups. The concept of quality varies according to the preparations for which the varieties are used. Although, some of the quality characteristics desired by grower, miller and consumer may be the same, yet each may place different emphasis on various quality characteristics.
Rice (Oryza sativa L. 2n=24) belongs to the family, Graminae and sub family Oryzoidea and is one ... more Rice (Oryza sativa L. 2n=24) belongs to the family, Graminae and sub family Oryzoidea and is one of the very few crop species endowed with rich genetic diversity which account over 100,000 landraces and improved cultivars. Genetic diversity is one of the most important factors with respect to crop improvement efforts. It plays a crucial role in progress and success of modern agriculture. Ever since the very beginning of agriculture (more than 10000 years ago) during the process of domestication and cultivation of crop plants, a wealth of genetic diversity has been utilized and partly preserved. Characterization and quantification of genetic diversity has long been a major goal in evolutionary biology. It is estimated that not even 15 % of the potential diversity has been utilized. Thousands of valuable allelic variations of traits of economic significance remain unutilized in nearly all crop plants. Though rice has become one of the most researched crops with wealth of scientific li...
Ninety-two rice (Oryza sativa L.) genotypes were evaluated during kharif 2013 to estimate the gen... more Ninety-two rice (Oryza sativa L.) genotypes were evaluated during kharif 2013 to estimate the genetic variability, heritability and correlation coefficients for 14 physicochemical and cooking quality traits. The experiment was conducted in a complete randomized block design with 3 replications. Highly significant (P < 0.01) differences were observed for all 14 quality characters studied. Among the traits, head rice recovery (%), water uptake, gel consistency and alkali spreading value exhibited high estimates of genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV). Highest broad sense heritability and genetic advance was obtained for head rice recovery (89% and 29%), milling (84% and 21%), water uptake (90% and 24%), amylose content (93% and 29%) and gel consistency (90% and 31%) which suggested that these traits would respond to selection owing to their high genetic variability and transmissibility. High estimates of heritability in association ...
Salinity is a serious problem all over the world with an average of 830 M ha being affected. In I... more Salinity is a serious problem all over the world with an average of 830 M ha being affected. In India, it’s about 13.3 M ha with coastal and inland salinity. The present study focused on effects of salinity on chlorophyll content, chlorophyll fluorescence, gas exchange parameters and osmotic potential in different salt concentration. The chlorophyll content reduced as salinity level increases and chlorophyll a and b concentration coincides with decrease in Fv/Fm ratio. The genotype IR72593 exhibited better survival response than the susceptible genotype IR29. The sensitive cultivar IR29 responds to salinity stress quickly and did not recover after one week of salinity stress which led to complete plant death. Tolerant genotypes showed lower reduction in gas exchange parameters, while IR29 showed sudden reduction during the initial hours of salt stress and decreased at 312 hours due to complete death of plants. Osmotic potential becomes negative with increase in salinity level irresp...
Globally, soil salinity has been on the rise owing to various factors that are both human and env... more Globally, soil salinity has been on the rise owing to various factors that are both human and environmental. The abiotic stress caused by soil salinity has become one of the most damaging abiotic stresses faced by crop plants, resulting in significant yield losses. Salt stress induces physiological and morphological modifications in plants as a result of significant changes in gene expression patterns and signal transduction cascades. In this comprehensive review, with a major focus on recent advances in the field of plant molecular biology, we discuss several approaches to enhance salinity tolerance in plants comprising various classical and advanced genetic and genetic engineering approaches, genomics and genome editing technologies, and plant growth-promoting rhizobacteria (PGPR)-based approaches. Furthermore, based on recent advances in the field of epigenetics, we propose novel approaches to create and exploit heritable genome-wide epigenetic variation in crop plants to enhance...
IntroductionThe case of combined drought and salinity stress is increasingly becoming a constrain... more IntroductionThe case of combined drought and salinity stress is increasingly becoming a constraint to rice production, especially in coastal areas and river deltas where low rainfall not only reduces soil moisture levels but also reduces the flow of river water, resulting in intrusion of saline sea-water. A standardized screening method is needed in order to systematically evaluate rice cultivars under combined drought+salinity at the same time because sequential stress of salinity followed by drought or vice-versa is not similar to simultaneous stress effects. Therefore, we aimed to develop a screening protocol for combined drought+salinity stress applied to soil-grown plants at seedling stage.MethodsThe study system used 30-L soil-filled boxes, which allowed a comparison of plant growth under control conditions, individual drought and salinity stress, as well as combined drought+salinity. A set of salinity tolerant and drought tolerant cultivars were tested, together with several ...
DRR Dhan 57 [IET 26171 (RP 5601-283-14-4-1)], an aerobic rice variety was developed from BPT5204/... more DRR Dhan 57 [IET 26171 (RP 5601-283-14-4-1)], an aerobic rice variety was developed from BPT5204/ Azucena cross combination. It was evaluated in AICRIP multi-location aerobic rice trials during the wet seasons of 2016 to 2020. DRR Dhan 57 consistently outperformed the check varieties in Eastern Zone (Zone III) and Central Zone (Zone V) with a mean grain yield of 4782 kg/ha, which is 13%, 17% and 16 % higher than the National, Zonal and Local checks, respectively. In addition, it exhibited moderate resistance to leaf blast and Neck blast; and to gall midge and rice thrips, and moderate resistance to planthoppers and whorl maggot. DRR Dhan 57 has a mid-early duration of 120 days (seed to seed) and possesses desirable grain and cooking quality parameters. It was released for cultivation in aerobic ecosystems of Jharkhand (Zone III), and Chhattisgarh (Zone V) states through Central Sub-committee on Crop Standards, Notification and Release of Varieties for Agricultural Crops; vide S.O. 8...
Journal of Agricultural Science and Technology, 2015
Pasting is one of the most important properties of wheat starch determining the flour quality and... more Pasting is one of the most important properties of wheat starch determining the flour quality and functionality. Twenty three New Plant Type (NPT) wheat derivatives along with three checks (PBW 343, HD 2329, and Raj 3765) have been studied in multi-location trials to assess the variation and environment induced fluctuations for their starch pasting properties. Although all flour pasting characteristics varied, Breakdown Viscosity (BV) and Setback Viscosity (SV) exhibited greater variability across environments. Additive Main effects and Multiplicative Interaction (AMMI) analysis indicated significant interactions between Genotypes and Environments Interaction (GEI) in starch pasting properties. Genotypes accounted largest proportion (39.78%) of the Sum of squares (SQ) for peak viscosity (PV) followed by environments (33.30%) and GEI (33.30%). Trough Viscosity (TV), GEI accounted for the largest proportion (40.44%) of the SQ followed by environments (31.76%) and genotypes (27.80%). G...
Genetic diversity was assessed among 40 wheat genotypes consisting of new plant type (NPT) wheat ... more Genetic diversity was assessed among 40 wheat genotypes consisting of new plant type (NPT) wheat derivatives, advanced breeding lines and released varieties since 1905 using 40 STMS markers. The total number of alleles amplified by 40 STMS markers was 113. The number of alleles amplified per STMS marker varied from one to six with an average of 3.32 alleles among the polymorphic markers. More alleles were detected for the B (3.55) genome derived STMS markers than A (3.18) and D (2.75) genomes. The maximum polymorphic information content (PIC) of 0.63 with an average of 0.35 was recorded while the PIC values for A, B, and D genomes were 0.243, 0.288 and 0.339 respectively. We identified 12 informative markers with three to six alleles and average of four alleles per marker and PIC values ranged from 0.31 to 0.63. Pair wise similarity coefficients ranged from 0.22 to 0.77 suggesting wider genetic diversity among wheat genotypes. The advanced breeding lines and NPT wheat derivatives exhibited different levels of diversity as compared with released cultivars since 1905 which could be utilized in widening the genetic base of wheat and as parental lines to tag as well as to mobilize useful traits for genetic improvement of wheat
Bacterial blight (BB) disease reduces the yield of rice varieties and hybrids considerably in man... more Bacterial blight (BB) disease reduces the yield of rice varieties and hybrids considerably in many tropical rice growing countries like India. The present study highlights the development of durable BB resistance into the background of an elite maintainer of rice, DRR17B, by incorporating two major dominant genes, Xa21 and Xa33 through marker-assisted backcross breeding (MABB). Through two sets of backcrosses, the two BB resistance genes were transferred separately to DRR17B. In this process, at each stage of backcrossing, foreground selection was carried out for the target resistance genes and for non-fertility restorer alleles concerning the major fertility restorer genes Rf3 and Rf4, using gene-specific PCR-based markers, while background selection was done using a set of 61 and 64 parental polymorphic SSR markers respectively. Backcross derived lines possessing either Xa21 or Xa33 along with maximum genome recovery of DRR17B were identified at BC3F1 generation and selfed to deve...
Rice (Oryzasativa.L.) is the staple food for more than half of the world population. Over 3 billi... more Rice (Oryzasativa.L.) is the staple food for more than half of the world population. Over 3 billion people in Asia alone derive 80% of their energy needs from rice. In addition to yield enhancement, quality improvement has now become the primary consideration in breeding programmes. Rice is the only cereal that is eaten as whole grain and human selection down the ages has given high preference to quality to cater to the needs of diverse rice based preparations. Grain quality in rice is difficult to define with precision as preference for quality varies from country to country and within the country from region to region and between ethnic groups. The concept of quality varies according to the preparations for which the varieties are used. Although, some of the quality characteristics desired by grower, miller and consumer may be the same, yet each may place different emphasis on various quality characteristics.
Rice (Oryza sativa L. 2n=24) belongs to the family, Graminae and sub family Oryzoidea and is one ... more Rice (Oryza sativa L. 2n=24) belongs to the family, Graminae and sub family Oryzoidea and is one of the very few crop species endowed with rich genetic diversity which account over 100,000 landraces and improved cultivars. Genetic diversity is one of the most important factors with respect to crop improvement efforts. It plays a crucial role in progress and success of modern agriculture. Ever since the very beginning of agriculture (more than 10000 years ago) during the process of domestication and cultivation of crop plants, a wealth of genetic diversity has been utilized and partly preserved. Characterization and quantification of genetic diversity has long been a major goal in evolutionary biology. It is estimated that not even 15 % of the potential diversity has been utilized. Thousands of valuable allelic variations of traits of economic significance remain unutilized in nearly all crop plants. Though rice has become one of the most researched crops with wealth of scientific li...
Ninety-two rice (Oryza sativa L.) genotypes were evaluated during kharif 2013 to estimate the gen... more Ninety-two rice (Oryza sativa L.) genotypes were evaluated during kharif 2013 to estimate the genetic variability, heritability and correlation coefficients for 14 physicochemical and cooking quality traits. The experiment was conducted in a complete randomized block design with 3 replications. Highly significant (P < 0.01) differences were observed for all 14 quality characters studied. Among the traits, head rice recovery (%), water uptake, gel consistency and alkali spreading value exhibited high estimates of genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV). Highest broad sense heritability and genetic advance was obtained for head rice recovery (89% and 29%), milling (84% and 21%), water uptake (90% and 24%), amylose content (93% and 29%) and gel consistency (90% and 31%) which suggested that these traits would respond to selection owing to their high genetic variability and transmissibility. High estimates of heritability in association ...
Salinity is a serious problem all over the world with an average of 830 M ha being affected. In I... more Salinity is a serious problem all over the world with an average of 830 M ha being affected. In India, it’s about 13.3 M ha with coastal and inland salinity. The present study focused on effects of salinity on chlorophyll content, chlorophyll fluorescence, gas exchange parameters and osmotic potential in different salt concentration. The chlorophyll content reduced as salinity level increases and chlorophyll a and b concentration coincides with decrease in Fv/Fm ratio. The genotype IR72593 exhibited better survival response than the susceptible genotype IR29. The sensitive cultivar IR29 responds to salinity stress quickly and did not recover after one week of salinity stress which led to complete plant death. Tolerant genotypes showed lower reduction in gas exchange parameters, while IR29 showed sudden reduction during the initial hours of salt stress and decreased at 312 hours due to complete death of plants. Osmotic potential becomes negative with increase in salinity level irresp...
Globally, soil salinity has been on the rise owing to various factors that are both human and env... more Globally, soil salinity has been on the rise owing to various factors that are both human and environmental. The abiotic stress caused by soil salinity has become one of the most damaging abiotic stresses faced by crop plants, resulting in significant yield losses. Salt stress induces physiological and morphological modifications in plants as a result of significant changes in gene expression patterns and signal transduction cascades. In this comprehensive review, with a major focus on recent advances in the field of plant molecular biology, we discuss several approaches to enhance salinity tolerance in plants comprising various classical and advanced genetic and genetic engineering approaches, genomics and genome editing technologies, and plant growth-promoting rhizobacteria (PGPR)-based approaches. Furthermore, based on recent advances in the field of epigenetics, we propose novel approaches to create and exploit heritable genome-wide epigenetic variation in crop plants to enhance...
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Papers by Suneetha Kota