Sutanu Sarkar

Molecular markers linked with bruchid resistance in Vigna radiata var. Sublobata and their validation

Bruchid, Callosobruchus chinensis (L.) is an important pest of Vigna radiata during storage. RFLP and PCR based markers identified, linked with bruchid resistance gene in wild accession of greengram (V. radiata var. Sublobata) either collected from Madagaskar or Australia. Whether these markers will be useful for marker assisted introgression of bruchid resistance gene from the Indian accession into the existing cultivars are not known. Here, we employed two STS based markers which were found earlier, to be linked with bruchid resistance gene in Australian accession ACC41. Only one primer pair, STSbr1 showed polymorphism among Indian Sublobata accession (Sub2) and other twelve green gram cultivars. Analysis of 113 segregating lines (F6) of a cross between a popular cultivar of West Bengal, B1 and Sub2 showed a cent percent co-segregation of resistant locus with the polymorphic fragment. STSbr1 behave as a dominant marker among Indian genotypes although it has been shown earlier a co-dominant banding pattern between ACC41 and other Australian Susceptible cultivars. Other STS marker, STSbr2, does not produce any polymorphic fragment among Sub2 and 18 greengram genotypes. STSbr1 employed in screening of 50 green gram accessions and found high efficiency in screening of bruchid resistant genotypes also. So STSbr1 will be useful for marker assisted selection and germplasm screening for development of bruchid resistant greengram.

Phosphate acquisition efficiency and phosphate starvation tolerance locus (PSTOL1) in rice

Phosphate availability is a major factor limiting tillering, grain filling vis-à-vis productivity of rice. Rice is often cultivated in soil like red and lateritic or acid, with low soluble phosphate content. To identify the best genotype suitable for these types of soils, P acquisition efficiency was estimated from 108 genotypes. Gobindabhog, Tulaipanji, Radhunipagal and Raghusail accumulated almost equal amounts of phosphate even when they were grown on P-sufficient soil. Here, we have reported the presence as well as the expression of a previously characterized rice gene, phosphate starvation tolerance locus (PSTOL1) in a set of selected genotypes. Two of four genotypes did not show any detectable expression but carried the gene. One mega cultivar, Swarna did not possess this gene but showed high P-deficiency tolerance ability. Increase of root biomass, not length, in P-limiting situations might be considered as one of the selecting criteria at the seedling stage. Neither the presence of PSTOL1 gene nor its closely-linked SSR RM1261, showed any association with P-deficiency tolerance among the 108 genotypes. Not only this, but the presence of PSTOL1 in recombinant inbred line (RIL) developed from a cross between Gobindabhog and Satabdi, also did not show any linkage with P-deficiency tolerance ability. Thus, before considering PSTOL1 gene in MAB, its expression and role in P-deficiency tolerance in the donor parent must be ascertained.

Sex-oriented research on dioecious crops of Indian subcontinent: an updated review

A number of dioecious species are grown across India and some of those plants play a crucial role in the agro-based economy of the country. The diagnosis of sex is very difficult in the dioecious plant prior flowering wherein sex identification at the seedling stage is of great importance to breeders as well as farmers for crop improvement or production purpose. A comprehensive approach of sex determination comprising morphological, biochemical, cytological and molecular attributes is a must required for gender differentiation in dioecious plant species. In the present review, we highlighted the economical, medicinal as well as industrial importance of most of the dioecious species extensively grown in Indian subcontinent. In addition to that, the cytogenetic, genetic as well as molecular information in connection to their sex determination were critically discussed in this review.

Cytological analysis for meiotic patterns in wild rice (Oryza rufipogon Griff.)

Highlights • Chromosomal patterns during meiosis as a fundamental cell division study in wild rice.• Normal meiosis occurs in most cases but in some instances meiotic abnormalities.• Comprises bi-nucleoli in first meiotic stages alike the cultivated species of Oryza.• Emphatically addresses the questions of high adaptability of wild rice.

Transgenic Research on Tomato: Problems, Strategies, and Achievements

Tomato is a climacteric fruit; it is widely consumed as vegetables worldwide either raw or cooked owing to the antioxidative and anticancer properties of lycopene, a dynamic carotenoid pigment of tomato. Nonetheless, since the past few decades, the productivity of tomato is compromised by an array of biotic and abiotic stresses along with deterioration of desirable quality parameters. Consequently, the development of stress-tolerant quality crops is a strategic challenge for agricultural biotechnology. Genetic transformation approach permits to insert defined gene simultaneously avoiding the elimination of any intrinsic genetic attributes unlike the occasion of conventional in situ or true in vitro screening. Till date, a number of attempts have been made to mitigate biotic and abiotic stress on tomato keeping the improvement of quality parameters in mind. Majority of such modifications comprise of the expression of stress-inducible genes, manipulation in the metabolic pathways, or the accumulation of low molecular compounds that function critically in retaining the agility of reactions. In this chapter, we offer an overview of the strategies based on frequently selected target sequences or molecules that are genetically transferred or modified to attain genetically transformed tomatoes tolerant to environmental stresses as well as to improve the quality traits of its fruits.

Role of irrigation and mulch in chickpea (Cicer arietinum L.) growth, productivity and moisture extraction pattern in Alluvial Zone of West Bengal, India

A field experiment was conducted at Research farm, BCKV, West Bengal during rabi 2010-11 and 2011-12 to evaluate the effect of irrigation and mulch on growth, nodulation, yield and water use efficiency of chickpea (Cicer arietinum L.). Chickpea irrigated at IW/CPE of 0.6 showed 7.14% and 23.53% higher seed yield compared to IW/CPE of 0.4 (0.98 t/ha) and Rainfed (0.85 t/ha), respectively and was significantly superior. Maximum seed yield of about 1.01 t/ha under the treatment receiving black polythene mulch, which was about 3.59%, 7.45% and 9.78% higher over the treatments receiving straw @ 5 t/ha, water hyacinth @ 5 t/ha and no mulch, respectively. Straw mulch @ 5 t/ha performed best regarding nodule dry weight and number per plant. Water use efficiency was highest with rainfed treatment and treatment receiving black polythene. Irrigation applied at IW/CPE of 0.6 maintained its superiority with highest net return, B:C, production and economic efficiency. Among mulches, highest return, B:C and efficiencies were recorded with the application of black polythene.

Inheritance of MYMIV tolerance in two RIL populations of greengram on lower Gangetic alluvial zone during summer and their parental molecular diversity

Inheritance of MYMIV tolerance was determined in two sets of recombinant inbred lines (RILs) of mungbean. The two sets comprising 143 and 79 RILs each derived from the cross between PM5 x Sub2 and B1 X Sub2, respectively were considered for the study. Sub2 was a Sublobata derived lines whereas, B1 was a popular small seeded cultivar of west Bengal, susceptible against MYMIV. It was observed that one or two major genes with a few modifiers played a significant role in resistance mechanism against MYMIV in the lower Gangetic alluvial zone. Resistance alleles for Sub2 and PM5 are probably allelic as observed from frequency distribution pattern. A set of 177 SSRs were employed for identification of polymorphism between parents. Only 37 SSRs showed polymorphism between Sublobata and B1 or PM5. But only eight SSRs were polymorphic between two high yielding cultivars. Markers linked with MYMIV tolerance like RGA, SCAR and others from earlier studies were also considered and found that only one RGA derived marker showed polymorphism between resistance and susceptible parents.