[Show abstract][Hide abstract] ABSTRACT: Water scarcity is threatening the sustainability of global food grain production systems. Devising management strategies and identification of crop species and genotypes are direly required to meet the global food demands with limited supply. This study, consisted of two independent experiments, was conducted to compare faba bean (Vicia faba L.) genotypes Giza Blanka, Goff-1, Hassawi-1, Hassawi-2 and Gazira-2 in terms of physiological attributes and yield under water-limited environments. In first experiment, conducted in a growth chamber, osmotic stress of −0.78, −0.96, −1.19 and −1.65 MPa was induced using polyethylene glycol for 4 weeks. In second experiment, conducted in open field for two consecutive growing seasons, water deficit treatments were applied 3 weeks after sowing. In this experiment, irrigation was applied when an amount of evaporated water from the ‘class A pan’ evaporation reached 50 mm (well watered), 100 mm (moderate drought) and 150 mm (severe drought). Water deficit, applied in terms of osmotic stress or drought, reduced the root and shoot length, related leaf water contents, total chlorophyll contents and efficiency of photosystem-II, plant height, grain yield and related attributes in faba bean; increased the leaf free proline, leaf soluble proteins and malondialdehyde contents, and triggered the maturity in tested faba bean genotypes. However, substantial genetic variation was observed in the tested genotypes in this regard. For instance, root length of genotypes Giza Blanka and Hassawi-2 decreased gradually, whereas it was increased in genotypes Goff-1, Hassawi-1 and Gazira-2 with increase in the level of osmotic stress. Genotypes Gazira-2 and Hassawi-2 had better relative leaf water contents, leaf free proline and soluble proteins under water deficit conditions; however, these were minimum in genotype Giza Blanka. Better accumulation of leaf free proline, soluble proteins, and maintenance of chlorophyll contents, tissue water, efficiency of photosystem-II and grain weight in water-limited conditions helped some genotypes like Hassawi-2 to yield better. Future breeding programs for developing new faba bean genotypes for water-limited environments may consider these traits.
Journal of Agronomy and Crop Science 08/2015; 201(4). DOI:10.1111/jac.12112 · 2.44 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A reliable regeneration system for faba bean (Vicia faba L.) has been difficult to establish, delaying its genetic improvement. In the present work a rapid, reproducible and efficient regeneration method was developed for faba bean using single cotyledon explants with half embryonal axis. MS medium supplemented with 6 mu M TDZ (thidiazuron), 10 mu M 2-iP and 4 mu M kinetin induced 30 to 50 adventitious buds /shoots after two weeks of culture, which were elongated on MS medium supplemented with 6 mu M 2-iP and 2 mu M kinetin. With healthy and strong roots established, shoots were transferred to MS medium supplemented with 5 mu M IBA within 10 to 14 days. Shoots of 5 cm long were most suitable for rooting. Potting-mixture with good aeration and less capacity to retain water was most suitable for successful establishment of faba bean plantlets. Garden soil mixed with sand (gravel) and bio-manure (1:1:1) was most suitable for transplantation. TDZ promoted adventitious bud formation while 5 mu M IBA was most suitable for rooting, higher concentrations were toxic to plantlets. Aeration of the potting mixture was important for rapid micropropagation and successful establishment. The efficient regeneration protocol reported here allows for successful micropropagation of faba bean, which is essential for future genetic improvement of plants via transformation protocols.
[Show abstract][Hide abstract] ABSTRACT: Chickpea production is limited worldwide because of abiotic and biotic stresses. Efforts to overcome these production constraints through traditional breeding are difficult due to limited genetic variation. Novel regeneration is pre-requisite for genetic transformation offers the opportunity to overcome hybridization barriers and introduce novel genes for resistance. Although direct gene transfer via direct DNA transfer has been reported, Agrobacterium mediated transformation is the preferred method and standard protocols have been established for the production of transgenic plantlets derived from co-cultivation of embryonic axes. This was soon adopted due to difficulties associated with regeneration of whole plants from callus. Only few reports have been reported using genetic transformation/ transgene(s) against abiotic stress tolerance transgenic chickpea plants. Transgenic chickpea using bacterial codA gene tolerance against abiotic stresses have been developed. Chickpea improvement and application of genomics tools to the study of the chickpea genome will be enhanced through the use of genetic transformation.
AFRICAN JOURNAL OF BIOTECHNOLOGY 02/2010; 9(6):782-797. · 0.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chloroplasts from plants of transgenic lines expressing prokaryotic choline oxidase gene (the codA(ps) gene; GenBank accession number-AY589052) and wild-type of chickpea and Indian mustard were evaluated for their efficacy to withstand photoinhibitory damage, by exposing them to high light intensity ( approximately 1200micromolm(-2)s(-1) photon flux density) at 10 and 25 degrees C. Western analysis confirmed presence of choline oxidase in chloroplasts of only transgenic lines. The loss in PS II activity in chloroplasts of wild-type exposed to high light intensity was significantly higher than that in chloroplasts of transgenic chickpea as well as Indian mustard. Although, chloroplasts of both wild-type and transgenic chickpea as well as Indian mustard were more sensitive to photoinhibitory damage at 10 than at 25 degrees C, the damage recorded in chloroplasts harboring choline oxidase was significantly lower than those of wild-type. High light promotes H(2)O(2) production in chloroplasts more significantly at low temperature (10 degrees C) than at 25 degrees C. We compared low temperature accelerated photoinhibition of chloroplasts with that caused due to exogenously applied H(2)O(2). Although exogenous H(2)O(2) accelerated high light intensity induced loss in PS II activity of chloroplasts of wild-type, it caused only a little alteration in PS II activity of chloroplasts from transgenic lines of both chickpea and Indian mustard, demonstrating that the chloroplasts harboring choline oxidase are better equipped to resist photoinhibition. We hypothesize that H(2)O(2) produced by choline oxidase as a byproduct during synthesis of glycinebetaine is responsible for building stronger antioxidant system in chloroplasts of transgenic lines compared to that of wild-type.
[Show abstract][Hide abstract] ABSTRACT: A rapid, reproducible and efficient regeneration method was developed for chickpea (Cicer arietinum L.) using single cotyledon with half embryonal axis as explants. MS medium supplemented with 4 ìM TDZ, 10 ìM 2-iP and 2 ìM kinetin induced 50-100 adventitious buds/shoots after 14 days of culture and elongated on MS medium supplemented with 5 ìM 2-iP and 2 ìM kinetin. Healthy, strong and 100 % rooting was achieved by exposing cut ends of the shoots to 10 sec pulse treatment with 100 ìmoles/ml IBA followed by their transfer to liquid MS basal medium within 10-14 d. 2-3 cm long shoots were most suitable for rooting. Potting-mixture with good aeration and lesser capacity to retain water was most suitable for achieving successful establishment of chickpea plantlets. Garden soil mixed with sand (gravel) and bio-manure in the ratio of 1:1:1 is most suitable for achieving cent percent transplantation success. Cent percent of plantlets got acclimatized, survived in the pots and showed normal growth, development, flowering followed by podding and seeds setting. Harvesting of seeds was done after the pods were fully matured and dry. In this communication, we have demonstrated for the first time that shoot length, pulse treatment of cut ends of shoots with 100 ìmoles/ml IBA and aeration of potting mixture are key factors for rapid micro-propagation and successful establishment of chickpea.
Physiology and Molecular Biology of Plants 10/2008; 14(4):329-35. DOI:10.1007/s12298-008-0031-1