Manjit S. Kang

Biotechnology and Drought Tolerance

Abiotic stresses present a major challenge in our quest for sustainable food production as these may reduce the potential yields by 70%u2009in crop plants. Of all abiotic stresses, drought is regarded as the most damaging. The complex nature of drought tolerance limits its management through conventional breeding methods. Innovative biotechnological approaches have enhanced our understanding of the processes underlying plant responses to drought at the molecular and whole plant levels. Hundreds of drought stress-induced genes have been identified and some of these have been cloned. Plant genetic engineering and molecular-marker approaches allow development of drought-tolerant germplasm. Transgenic plants carrying genes for abiotic stress tolerance are being developed for water-stress management. Structural genes (key enzymes for osmolyte biosynthesis, such as proline, glycinebetaine, mannitol and trehalose, redox proteins and detoxifying enzymes, stress-induced LEA proteins) and regulatory genes, including dehydration–responsive, element-binding (DREB) factors, Zinc finger proteins, and NAC transcription factor genes, are being used. Using Agrobacterium and particle gun methods, transgenics carrying different genes relating to drought tolerance have been developed in rice, wheat, maize, sugarcane, tobacco, Arabidopsis, groundnut, tomato, and potato. In general, the drought stress-tolerant transgenics are either under pot experiments or under contained field evaluation. Drought-tolerant genetically modified (GM) cotton and maize are under final field evaluations in the United States. Molecular markers are being used to identify drought-related quantitative trait loci (QTL) and their efficient transfer into commercially grown crop varieties of rice, wheat, maize, pearl millet, and barley.

Biotechnology and Crop Improvement

Plant biotechnology, a major component of agricultural biotechnology, deals with various aspects of plant tissue culture, genetic transformation, and molecular biology techniques. Tissue culture methods offer a rich scope for creation, conservation, and utilization of genetic variability for the improvement of field, fruit, vegetable, and forest crops, and medicinal/aromatic plants. Micropropagation technology ensures true to type, rapid and mass multiplication of plants that possesses special significance in vegetatively propagated plant species. This technology has witnessed a huge expansion globally, with an estimated global market of 15 billion US

Gene Expression Browser: large-scale and cross-experiment microarray data integration, management, search & visualization

/annum for tissue-culture products. Some basic techniques of tissue culture, such as anther/microspore culture, somaclonal variation, embryo culture, and somatic hybridization, are being exploited to generate useful genetic variability for obtaining incremental improvement in commercial cultivars. Production of secondary metabolites, such as food flavors, food colors, dyes, perfumes, drugs, and scented oils used in aromatherapy, through cell cultures and hairy root cultures, are leading examples of molecular farming. Cryopreservation of germplasm at the cell/tissue/organ levels, in liquid nitrogen at −196°C, is highly rewarding for establishing germplasm banks, especially for vegetatively propagated crops and rare, endangered plant species. During the past 15 years, remarkable achievements have been made in the production, characterization, field evaluation, and release of transgenic varieties/hybrids in several crops. Transgenic varieties/hybrids of maize, cotton, soybean, potato, tomato, and papaya are now being commercially grown on about 134 million hectares spread across 25 countries. Research in genomics allows high-resolution genetic analysis for physical mapping and positional gene cloning of useful genes for crop improvement. Molecular (DNA) markers help in precise characterization of germplasm, construction of saturated linkage maps, and DNA fingerprinting of crop varieties. Molecular markers are now increasingly being used for marker-assisted gene pyramiding and alien gene introgression. Current research, involving large-scale DNA sequencing, microarrays, and robotics, is heading towards gene revolution and nanobiotechnology.

Repeatability between two intermediate sugarcane genotype selection stages in Florida.

BackgroundIn the last decade, a large amount of microarray gene expression data has been accumulated in public repositories. Integrating and analyzing high-throughput gene expression data have become key activities for exploring gene functions, gene networks and biological pathways. Effectively utilizing these invaluable microarray data remains challenging due to a lack of powerful tools to integrate large-scale gene-expression information across diverse experiments and to search and visualize a large number of gene-expression data points.ResultsGene Expression Browser is a microarray data integration, management and processing system with web-based search and visualization functions. An innovative method has been developed to define a treatment over a control for every microarray experiment to standardize and make microarray data from different experiments homogeneous. In the browser, data are pre-processed offline and the resulting data points are visualized online with a 2-layer dynamic web display. Users can view all treatments over control that affect the expression of a selected gene via Gene View, and view all genes that change in a selected treatment over control via treatment over control View. Users can also check the changes of expression profiles of a set of either the treatments over control or genes via Slide View. In addition, the relationships between genes and treatments over control are computed according to gene expression ratio and are shown as co-responsive genes and co-regulation treatments over control.ConclusionGene Expression Browser is composed of a set of software tools, including a data extraction tool, a microarray data-management system, a data-annotation tool, a microarray data-processing pipeline, and a data search & visualization tool. The browser is deployed as a free public web service (http://www.ExpressionBrowser.com) that integrates 301 ATH1 gene microarray experiments from public data repositories (viz. the Gene Expression Omnibus repository at the National Center for Biotechnology Information and Nottingham Arabidopsis Stock Center). The set of Gene Expression Browser software tools can be easily applied to the large-scale expression data generated by other platforms and in other species.

Improved seeds and green revolution.

Improved yield and disease resistance on sand soils are priorities of the Canal Point (CP) sugarcane (Saccharum spp.) breeding and selection program. Analyses of historical phenotypic data can provide helpful information in guiding selection strategies to meet these priorities. Correlation analysis was used to examine repeatability of phenotypic data used to advance genotypes from an unreplicated single location clonal crop test (stage II) to the subsequent stage (stage III; two replicate, four location clonal crop experiment). Correlations between data for four traits measured in stage II and the corresponding data pooled across soil types for the same genotypes in stage III varied across 23 series of the CP program. Generally, when correlations were statistically significant (P < 0.05), correlation values were low (means; theoretical recoverable sucrose (TRS) r = 0.40, cane yield r = 0.27, and economic index r = 0.23). Similar trends were evident for correlations between data from stage II and stage III on muck soil and stage II and stage III on sand soil across 10 series of the CP program. A 10% reduction in the number of genotypes advanced to stage III over that period would have meant losing only 1 and 13 genotypes that had commercial potential on muck and sand soils, respectively (n = 1278). Correlations between the phenotypic data were significant only for stage III comparisons between TRS and cane yield, which were negatively associated on either soil type. These results indicate that changes in the advancement strategy from stage II are not required as advancing approximately 135 genotypes identifies almost all genotypes with the genetic potential to yield well on muck or sand soils in stage III. Increasing genotypes in stages prior to stage III and changing crossing strategies to improve identification of disease-resistant, high-yielding genotypes for sand soils is recommended.

Improving Grain Yield and Yield Components of Temperate Maize Using Tropical Germplasm

The purpose of this review is to share with developing countries how a dedicated agricultural university helped enhance food production and thwart Malthusian scenario. The Indian adequacy on the food-front has largely been attributed to the development of improved seeds of different crops, in particular wheat and rice, efficient system of agro-technology generation and its transfer to farmers, and useful coordination between state development departments and suitable government policies. We have discussed the revolutionary role of Punjab Agricultural University (PAU) in transforming a food-deficient India into a food self-sufficient nation. This dramatic transformation is dubbed the Green Revolution. Fueled by scientific research, PAU has, since its inception in 1962, released more than 580 improved varieties/hybrids of field crops, vegetables, fruits, fodder, and ornamentals. Now, almost the entire cropped area of the Punjab state is under improved varieties. This is because PAU has one of the best seed-production and delivery programs among agricultural universities in India. Its total seed production capacity during the last five years was >30,000 tons. Millions of disease-free nursery plants of fruits and ornamentals are supplied to farmers annually. The seed-production technology, together with an improved seed-distribution system, has given an impetus to agriculture in recent years. New breeding methods and modern technologies, such as biotechnology, electron microscopy, and nanotechnology, should provide even better seeds in the future. The scanning electron microscopy facilities at PAU have helped distinguish between seed surfaces of drought-resistant and drought-susceptible genotypes of Indian mustard, and, revealed that seed coat microstructure could be used as a selection criterion for stress tolerance. Farmer training in the production of hybrid seed and nursery help boost seed production and farmers income. The seed-plot technique in potato and rhizobium inoculation of pulse seeds have had a strong impact on production. The supply of high-quality mushroom spawn and quality Kinnow (citrus) plantlets to farmers has boosted mushroom and citrus production, and thereby the farmers incomes. Ever-increasing population requires universities, such as PAU, to continue to play pivotal roles in enhancing food production. Seed production programs will need to be put on a new trajectory to double food production by 2050 and agricultural universities would need to be strengthened to meet this critical goal.

GGE Biplot Analysis for Cane and Sugar Yield from Advanced-Stage Sugarcane Trials in Subtropical India

The objectives of this study were: (1) to determine general combining ability (GCA) of 25 inbred lines selected from CIMMYT populations, specific combining ability (SCA), heterotic specific-group combining ability (HSPGCA) of testcrosses from these 25 lines, using four testers; (2) to determine optimum number of testers for evaluating a large number of exotic lines. The 25 exotic lines were crossed with four elite local maize inbred lines (a line × tester design). A randomized complete-block design with three replications was used at two locations. Data on grain yield and five yield-component traits were recorded. Combining ability analysis showed 8 exotic lines to be genetically similar to the testers and could be assigned to the two current maize heterotic groups. Correlation analysis indicated that one tester had correctly selected the top best lines from a large number of exotic lines. However, when line × location interaction is significant, exotic line performance should be evaluated at multiple locations or multiple years or both.

Molecular Clustering and Interrelationships among Agronomic Traits of Jordanian Barley Cultivars

The performance of quantitative traits in sugarcane (Saccharum spp. complex) often varies across diverse environments because of significant genotype-by-environment interaction (GEI). Our objective was to assess performance stability of 20 advanced sugarcane genotypes across six environments, including two crop seasons in Punjab. Data were obtained on cane yield (t/ha), sucrose % juice, and commercial cane sugar % at harvest and subjected to GGE [genotype (G) plus genotype-environment (GE)] biplot analysis, which revealed high positive correlations between spring and autumn crop seasons at all locations for all measured traits. This implied that genotypes could be evaluated in either crop season, which should reduce testing cost and time. Test environment Faridkot (FDK) spring, being both discriminating and representative, was an ideal test environment for selecting generally adapted genotypes for cane yield. Similarly, Ludhiana (LDH) autumn was an ideal test environment for selecting generally adapted genotypes for quality traits. Co 0238 and CoPb 08214, having high mean performance and stability across environments for cane yield and quality traits, were identified as ideal genotypes. These genotypes can be exploited commercially for the entire state of Punjab. The GGE biplot helped identify a specifically adapted genotype, CoH 119, which was the best performer in Gurdaspur (GDSP) in both crop seasons.

Genetic and Phenotypic Path Analyses and Heritability in Sugarcane 1

To make barley breeding programs more effective, comprehensive information on the amount of molecular diversity in barley cultivars and on interrelationships among agronomic traits is needed. Path-coefficient and principal-component analyses were used to study the interrelationships among barley grain yield and various grain yield components. Eleven amplified fragment-length polymorphism (AFLP) primer combinations were used to cluster barley cultivars into distinct groups. Path analysis across cultivars showed that number of fertile tillers per plant had the largest positive direct effect (0.94) on grain yield, followed by biological yield (0.491), and spike weight (0.357). However, number of tillers per plant (−0.917) and spike length (−0.263) showed negative direct effects. Principal component analysis using GGEbiplot showed that ‘Rum’ cultivar had the highest values for biological yield, spike weight, plant height at maturity, leaf width, peduncle length, and days to heading. It also had the highest grain yield, followed by Acsad-176; the other three cultivars yielded below average. This cultivar separation was confirmed by cluster analysis. Such molecular and morphological differentiation should be of great help for barley breeding programs.