Plant Biotechnology – Technologies Developed

Tamil Nadu Agricultural University > Centre for Plant Molecular Biology and Biotechnology > Plant Biotechnology – Technologies Developed

Major Research Accomplishments

  • Anna-4, a drought tolerant rice variety suitable for rainfed cultivation was released for cultivation  in southern districts
  • A meta-QTL 1 spanning ~3.0 Mb between RM585 and RM217) on chromosome 6 mapped usinga local rice landrace, Norungn was further fine mapped to 94.0 kb (0.36 cM) between markers, RM2434 and RM6773 and deployed in MAB.
  • Another meta-QTL, qDTY1.1 for rice yield under drought in TPE was mapped on chromosome 1 using the landrace, Nootripathu with an interval of about 3.8 cM between RM212-RM302-RM8085-RM3825 and is being fine mapped.

Performance of IR20 NILs under rainfed conditions

  • Near-isogenic lines for root trait QTLs have been developed through MAB by introgressing QTLs for deep root growth from Columbian rice into IR20. NILs were evaluated under drought in TPE during 2010-11, 2011-12, 2012-13, 2013-14 and 2014-15 rainfed cropping seasons. NILs with higher yield under drought in TPE have been identified.
  • Near-isogenic lines for root trait QTLs have been developed through MAB by introgressing QTLs for deep root growth from Columbian rice into IR20. NILs were evaluated under drought in TPE during 2010-11, 2011-12, 2012-13, 2013-14 and 2014-15 rainfed cropping seasons. NILs with higher yield under drought in TPE have been identified.

  • Genes for drought and salinity tolerance are isolated from diverse plant sources (drought tolerant rice, finger millet and resurrection plants) to improve abiotic stress tolerance in rice and other major crops.

  • Constructed chimeric cry2AX1 gene using part of indigenous cry2Aa and cry2Ac sequences. In artificial diet based bioassay, Cry2AX1 showed higher level of toxicity against H. armigera than its parental proteins (Patent # 24427).

  • Transgenic tobacco expressing Cry2AX1 protein (1.5 to 2 µg / g fresh leaf tissue) showed 100% mortality in 1st to 4th instar larvae of Helicoverpa armigera and about 90% mortality in neonates of Spodoptera litura.

  • A transgenic cotton event with single locus integration of cry2AX1 gene showed expression of about 1.0µg / g fresh leaf tissue and 80 to 90% mortality in neonates of H. armigera.

  • Transgenic rice expressing 0.1 to 0.15 µg Cry2AX1 / g fresh leaf tissue showed about 80 per cent mortality in rice leaf folder larvae.

  • cry2Ai gene encoding a novel insecticidal protein (holotype) of Bt was isolated for the first time during 2009. Earlier holotypes of Cry2A were isolated in USA, Korea, Australia and China.
  • A T2 progeny of transgenic tomato event with single locus integration of novel cry2A gene showing 0.5 to 0.7 µg Cry2A / g fresh leaf tissue recoded 100% mortality in Helicoverpa armigera

Bioassay on Helicoverpa armigera

  • A traditional therapeutic rice “Kavuni” is characterized for biochemical and molecular composition.  High yielding, semi-dwarf and photo-insensitive rice lines possessing all major therapeutic clues of have been developed through molecular breeding.

  • As a first step towards enhancing iron content in rice, genes involved in iron homeostasis such as IRT2 gene from barnyard millet, NAS2 gene from rice, ferritin gene from soybean were cloned and characterized. Golden rice versions of local elite rice lines (ADT43 and ASD16) developed.
  • A phytase gene was isolated from Aspergillus niger and introduced into maize under the control of an endosperm specific zein promoter. Expression of phytase in maize endosperm decreased phytic acid content while enhanced phosphorous content.
  • A Laboratory protocol “Agro-inoculation” was optimized for screening mung bean germplasm against MYMV. MYMV resistant green gram genotypes have been identified and used for the development of mapping population. Inter-specific cross derivatives derived between mung bean and rice bean exhibiting resistance against MYMV identified and used for developing further segregating progenies

  • High efficiency regeneration and transformation protocol in banana have been standardized for hill banana. With an aim of developing Bunchy Top Virus resistant banana, thirty five events of Rasthali, harbouring RNAi construct targeting CP, MP and rep genes of BBTV have been generated.

                                

Banana transformation

  • With a view to developing dihaploid lines in tomato, brinjal and cocoa, anther culture studies are being carried out.
  • Towards Identification of molecular targets for management of crop pests using RNAi approach, genes encoding chemosensory proteins in Spodoptera litura and Nilaparvata lugens were cloned. Silencing of OR83b and CHSA genes of Spodoptera litura resulted in reduced feeding and developmental deformities in larvae.
  • Genetic analysis of phosphine resistance among storage pests revealed that rph2 allele frequency varied in different storage pests and different food grain reserves. The frequency of resistance was above 50 percent in most of the populations.
  • Genetic diversity and phylogeography analyses of three species of honey bees from 8 states of India were carried out. Different population clusters were recorded.
  • Different coumarins viz., auraptene, imperatorin, heraclenin and umbelliferone were isolated from Aegle marmelos correa and osthole, phellopterin & imperatorin were isolated from Angelica archangelica Linn. Ritter Reaction was performed on the isolated compounds.

 

Products in the pipeline:

  • Submergence tolerant version of a popular rice variety CO 43 namely (CO 43 – Sub1) developed through MABB and tested under MLT for the second year. This showed >90% RPG recovery and performed on-par with the recurrent parent under normal conditions.

  • IR 20 NILs introgressed with root QTLs of CT9993 possessing higher yield under drought have been identified and tested under TPE for 4 years.

IR20 NILs

  • NILs of a popular rice variety “Improved White Ponni (IWP)” introgressed with saltol QTL of FL 478 through MABB are tested under MLT. NILs were found to perform better than recurrent parent (IWP) and are in the second year of testing.

  • Two promising rice lines namely CBMAS14065 (medium duration (130 days), high yield, short slender grain, and harboring 2 major drought tolerant QTLs of Apo) and CBMAS14142 (early duration (120 days) high yield, long slender grain (Length – >7 mm and breadth – >2 mm) and harboring 3 major drought tolerant QTLs of Apo) have been nominated for evaluation under MLT.
  • Two promising rice lines namely CBMAS14065 (medium duration (130 days), high yield, short slender grain, and harboring 2 major drought tolerant QTLs of Apo) and CBMAS14142 (early duration (120 days) high yield, long slender grain (Length – >7 mm and breadth – >2 mm) and harboring 3 major drought tolerant QTLs of Apo) have been nominated for evaluation under MLT.

     

CBMAS14065                                                                      CBMAS14142

  • High yielding and photo-insensitive versions of traditional therapeutic rice “Kavuni” have been developed through molecular breeding and tested under PYT.