http://nopr.niscair.res.in/handle/123456789/10039 <b>Special Issue on Plant Molecular Biology and Biotechnology</b> Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/11293 Title: Plant Insecticidal Proteins and their Potential for Developing Transgenics Resistant to Insect Pests <br/> <br/>Authors: Koundal, K R; Rajendran, P <br/> <br/>Abstract: Insects cause heavy damage to cultivated crop plants. Production of proteinaceous inhibitors that interfere with the digestive biochemistry of insect pests is one of the naturally occurring defence mechanisms in plants. These proteins include lectins, arcelins and inhibitors of alpha amylases and proteases of various larvae pests. Use of plant genes encoding effective inhibitors of major digestive enzymes, such as protease and a-amylase inhibitors of the target pest species is emerging as viable approach for the production of pest resistant transgenic crop plants. Therefore, it is important to characterize proteins and their genes from our indigenous crops in order to strengthen and broaden our gene bank for pest control manipulations. The availability of diverse insecticidal proteins and their genes from different plant species will make it easier to use one or more genes in combination to develop resistant crop plants. Eventually, insect resistant transgenic plants will certainly prove more economic than any conventional control strategy if long-term benefit of transgenic crops especially factors such as environmental damage and human health risks are considered. <br/> <br/>Page(s): 110-120 http://nopr.niscair.res.in/handle/123456789/11292 Title: Molecular Diagnosis and Application of DNA Markers in the Management of Fungal and Bacterial Plant Diseases <br/> <br/>Authors: Sharma, T R <br/> <br/>Abstract: Successful management of plant diseases is mainly dependent on the accurate and efficient detection of plant pathogens, amount of genetic and pathogenic variability present in a pathogen population, development of disease resistant cultivars and deployment of effective resistance genes in different epidemiological regions. Beside conventional methods of pathogen detection and breeding resistant cultivars, recent developments in molecular biology techniques particularly the advent of various DNA markers have greatly influenced the plant protection methods. Pathogen detection has relied on isolation of microorganisms and observations of symptoms they induce on susceptible hosts. In many situations cultural, morphological and chemical markers have been used to study variation in pathogen populations. Such markers are limited, often unstable and are influenced by environmental conditions. Molecular detection of plant pathogens and characterization of genetic variability by using different DNA markers have offered additional tools in the hands of plant pathologists and plant breeders. Various PCR based and hybridization based DNA marker techniques can be used for the characterization of genetic variability in pathogens and molecular tagging of disease resistance genes. DNA markers linked to specific resistance gene can be used in marker-assisted-selection for resistance breeding, gene pyramiding and map-based cloning of the resistance genes. In this communication various uses of DNA markers in pathogen diagnostics and mapping, pyramiding and map-based cloning of disease resistance genes have been discussed. <br/> <br/>Page(s): 99-109 http://nopr.niscair.res.in/handle/123456789/11291 Title: Molecular Breeding for Maize Improvement: An Overview <br/> <br/>Authors: Prasanna, B M; Hoisington, D <br/> <br/>Abstract: The maize genome is one of the most extensively analyzed among the plant genomes. Consequently, maize has been at the forefront in development and evaluation of an array of molecular markers for varied purposes in genetics and breeding. Besides the well-demonstrated utility of molecular markers in genotype differentiation and analysis of genetic diversity in maize germplasm, application of DNA-based markers is also of considerable significance to tropical/sub-tropical maize production systems, such as in India, for mapping and marker-assisted selection for resistance to major biotic/abiotic stresses affecting production and productivity. Significant impetus in this direction has been provided in recent years through the Asian Maize Biotechnology Network (AMBIONET). This article provides an overview of the recent efforts under AMBIONET in relation to: (i) the molecular characterization of inbred lines developed by various public sector institutions in India; (ii) the analysis of genetic diversity in the Indian maize germ plasm using microsatellite markers; and (Hi) the mapping of quantitative trait loci conferring resistance to different downy mildews affecting maize in tropical Asia. Judicious integration of conventional and molecular approaches in maize breeding programmes is vital for efficient utilization of genetic resources, and improving the production and post-harvest characteristics of the elite germplasm. This shall, in turn, require further strengthening of synergistic linkages and partnerships among national and international research institutions to harness the rapidly emerging information and technologies related to molecular breeding in maize. <br/> <br/>Page(s): 85-98 http://nopr.niscair.res.in/handle/123456789/11290 Title: Protoplast Fusion and Brassica Improvement <br/> <br/>Authors: Kirti, P B; Prakash, S; Bhat, S R; Chopra, V L <br/> <br/>Abstract: <i>Brassica </i>coenospecies has been bestowed with a large collection of wild and weedy relatives, which could act as donors of genes controlling agronomically important traits like disease resistance, yield attributes, modified fatty acid composition in the seed etc. Additionally, the cytoplasm of these species could be the sources for developing alloplasmic male sterility systems that are important in developing hybrid mustard varieties. The technology of protoplast culture and protoplast fusion has been very well developed for crop Brassicas and this could be effectively exploited in developing somatic hybrids and cytoplasmic hybrids, in short called as cybrids. This could pave the way for overcoming problems associated with the development of incompatibility barriers and allow for obtaining hybrids of the wild species with the cultivated species and manipulating characters that are controlled by organelle genomes. In <i>Nicotiana </i>species, protoplast fusion resulted in the development of novel mitochondrial genomes and plants carrying novel genomes have differing flower morphology. Protoplast fusion in <i>Cruciferae </i>also nearly invariably results in mitochondrial genome recombination/rearrangement. Hence, protoplast fusion can be effectively utilized in manipulating flower morphology and male sterility in crop Brassicas. <br/> <br/>Page(s): 76-84