Synseed conception for short-term storage,germplasm exchange and potentialities of regeneration genetically stable plantlets of desert date tree (Balanites aegyptiaca Del.)

Synthetic seed has become a proficient tool that facilitates conservation as well as mass propagation of elite plant species by encapsulating somatic embryo or meristem tissue. Inclusion of meristematic tissues instead of somatic embryos hastens widespread utilization of this technology in recent years. Synseeds offer short term conservation of germplasms, provide readily available tissue source for easy mass propagation where each synseeds can virtually act as zygotic seeds giving rise to plantlets. This is the first report on synseed production following the confirmation of the genetic homogeneity in regenerated plantlets of Balanites aegyptiaca Del. (L.) using ISSR marker system. In this study, nodal segments, excised from in vitro proliferated shoot cultures developed from mother plant, were encapsulated in calcium alginate beads and the finest gel complexation was achieved using 3 % sodium alginate and 100 mM CaCl₂·2H₂O. Maximum percent response (80 %) for conversion of encapsulated nodal segments into plantlets was obtained on Murashige and Skoog (MS) medium containing 12.5 μM benzyladenine and 1.0 μM α-naphthalene acetic acid. Encapsulated nodal segments could be stored at low temperature (4 °C) up to 4 weeks with a survival frequency of 82 %. The regenerated shoots were rooted on half strength MS medium augmented with 1.0 μM indole-3-butyric acid. Well-developed plantlets regenerated from encapsulated nodal segments were acclimatized successfully with 90 % survival frequency. Fingerprinting profiles of the regenerated plantlets derived from synseeds and the donor plant were generated using a total of 20 ISSR primers, of which 14 primers produced distinct, reproducible amplified products. A total of 158 scorable bands were obtained from the complete amalgamation of primers and plantlets and 98.7 % bands were monomorphic across the plantlets which indicate that this micropropagated line derived from synseed is genetically stable and demonstrates the reliability of our protocol for short term conservation, germplasm exchange and distribution of identical plants.     

Mapping QTL for resistance to botrytis grey mould in chickpea

Botrytis grey mould (BGM) caused by Botrytis cinerea Pers. ex. Fr. is the second most important foliar disease of chickpea (Cicer arietinum L.) after ascochyta blight. An intraspecific linkage map of chickpea consisting of 144 markers assigned on 11 linkage groups was constructed from recombinant inbred lines (RILs) of a cross that involved a moderately resistant kabuli cultivar ICCV 2 and a highly susceptible desi cultivar JG 62. The length of the map obtained was 442.8 cM with an average interval length of 3.3 cM. Three quantitative trait loci (QTL) which together accounted for 43.6% of the variation for BGM resistance were identified and mapped on two linkage groups. QTL1 explained about 12.8% of the phenotypic variation for BGM resistance and was mapped on LG 6A. It was found tightly linked to markers SA14 and TS71rts36r at a LOD score of 3.7. QTL2 and QTL3 accounted for 9.5 and 48% of the phenotypic variation for BGM resistance, respectively, and were mapped on LG 3. QTL 2 was identified at LOD 2.7 and flanked by markers TA25 and TA144, positioned at 1 cM away from marker TA25. QTL3 was a strong QTL detected at LOD 17.7 and was flanked by TA159 at 12 cM distance on one side and TA118 at 4 cM distance on the other side. This is the first report on mapping of QTL for BGM resistance in chickpea. After proper validation, these QTL will be useful in marker-assisted pyramiding of BGM resistance in chickpea.     

ANTIOXIDANT DEFENSE MECHANISM IN PIGEON PEA UNDER COBALT STRESS

Influence of excess cobalt (Co; 10 to 400 μM Co) on growth, biomass, Co accumulation, photosynthetic pigments, lipid peroxidation, proline, non-protein thiols and cysteine contents as well as activities of anti-oxidative enzymes was studied in pigeon pea (Cajanus cajan Mill). In pigeon pea leaves decreased concentrations of chlorophyll and carotenoids on exposure to excess Co was associated with decrease activity of catalase and super oxide dismutase and suggest antiperoxidative nature of excess Co. However, a marked increase in the activities of ascorbate peroxidase and peroxidase and enhanced levels of cysteine, non-protein thiols, and proline are suggestive of induction of antioxidants in excess Co. The threshold of toxicity (10% growth reduction) and toxicity (33% growth reduction) values of Co in pigeon pea were 75 and 160 μg g^?1in leaves, 42 and 180 μg g^?1in stem and 50 and 340 μg g^?1Co in roots, respectively.     

Inverse method for operational control of canal systems

A non-linear explicit inverse solution method for the operational control of remotely controlled canal systems is presented. The model accounts for canal seepage, turnout flows (point sink), control structures with steeply varying and/or discontinuous discharge characteristics. The governing unsteady flow equations are solved backward both in space and time. For each space interval, the use of finite difference approximations for the operational problem results in a system of two non-linear equations in two unknowns. These equations are solved using Newton's method. The method is extended to canal networks. The canal junctions are classified into three types. The controllability of flow for each type of canal junction and for the network as a whole are discussed. The model, though explicit, is found to be unconditionally stable. The model results are verified with the unsteady flow simulation model based on non- linear Preissmen's scheme. The applicability of the model to a canal system is demonstrated.     

Consistent Variation Across Soil Types in Salinity Resistance of a Diverse Range of Chickpea (Cicer arietinum L.) Genotypes

Chickpea is considered sensitive to salinity, but the salinity resistance of chickpea germplasm has rarely been explored. This study aimed to (i) determine whether there is consistent genetic variation for salinity resistance in the chickpea minicore and reference collections; (ii) determine whether the range of salinity resistance is similar across two of the key soil types on which chickpea is grown; (iii) assess the strength of the relationship between the yield under saline conditions and that under non‐saline conditions; and (iv) test whether salinity resistance is related to differences in seed set under saline conditions across soils and seasons. The seed yield of 265 chickpea genotypes in 2005–2006 and 294 cultivated genotypes of the reference set in 2007–2008 were measured. This included 211 accessions of the minicore collection of chickpea germplasm from the International Crops Research Institute for the Semi‐Arid Tropics (ICRISAT). The experiments were conducted in a partly controlled environment using a Vertisol soil in 2005–2006 and an Alfisol soil in 2007–2008, with or without 80 mm sodium chloride (NaCl) added prior to planting. In a separate experiment in 2006–2007, 108 genotypes (common across 2005–2006 and 2007–2008 evaluations) were grown under saline (80 mm NaCl) and non‐saline conditions in a Vertisol and an Alfisol soil. In 2005–2006 in the Vertisol and 2007–2008 in the Alfisol, salinity delayed flowering and maturity, and reduced both shoot biomass and seed yield at maturity. There was a large variation in seed yield among the genotypes in the saline pots, and a small genotype by environment interaction for grain yield in both soil types. The non‐saline control yields explained only 12–15 % of the variation of the saline yields indicating that evaluation for salinity resistance needs to be conducted under saline conditions. The reduction in yield in the saline soil compared with the non‐saline soil was more severe in the Alfisol than in the Vertisol, but rank order was similar in both soil types with a few exceptions. Yield reductions due to salinity were closely associated with fewer pods and seeds per pot (61–91 %) and to lesser extent from less plant biomass (12–27 %), but not seed size. Groups of consistently salinity resistant genotypes and the ones specifically resistant in Vertisols were identified for use as donor sources for crossing with existing chickpea cultivars.     

Salicylic acid content of spices and its implications

This work was done to determine the salicylate content of a variety of commonly used spices and to assess whether this potential dietary source of salicylate was bioavailable. Spices, Indian cooked dishes, and blood and urine samples taken after ingestion of a test meal were investigated for their salicylate content using high-performance liquid chromatography with electrochemical detection. The serum salicylic acid concentrations in samples from villagers in southern India were also measured and have been compared with typical European values. Salicylic acid was determined in all spices (up to 1.5 wt %) and cooked dishes. The salicylate content of blood and urine was shown to increase following consumption of the meal, indicating that this dietary source of salicylic acid was bioavailable. Salicylic acid levels in the serum from rural Indians were significantly (median almost 3-fold) higher than values previously measured in Western vegetarians. Chemoprotective aspirin is rapidly hydrolyzed to salicylic acid, and this phytochemical may contribute to the low cancer incidence in rural India.     

Studies on some biochemical characteristics of Staphylococcus aureus of buffalo mammary origin

A total of 49 isolates of Staphylococcus aureus of buffalo mammary origin were studied for biochemical characteristics. Coagulase production, clumping factor, haemolytic activity, pigment production and fermentation of maltose and mannitol were employed to differentiate S. aureus from S. hyicus and S. intermedius. Out of 49 isolates, 97.95, 93.87, 93.87, 89.79, 95.91, 100.0, 95.91, 59.18, 100.0, 100.0, 100.0, 89.79, 91.83 and 100.0% isolates were positive for coagulase production, protein-A production, haemolysin production, thermostable nuclease production, deoxyribonuclease production, tellurite reduction, nitrate reduction, lipase production, phosphatase production, mannitol fermentation, glucose fermentation, M.R. test, V.P. test and pigment production respectively. The only isolate from which coagulase production could not be detected, however, showed haemolytic activity, protein-A productivity, pigmentation and mannitol fermentation. One of the protein-A negative isolate was coagulase positive and showed mennitol fermentation, pigmentation and haemolytic activity. The study revealed that the biochemical characteristics of S. aureus of buffalo mammary origin did not differ from those of cattle origin. Coagulase, haemolysin, thermostable nuclease, deoxyribonuclease, phosphatase, lipase, tellurite and nitrate reduction closely related with protein-A. The presence of protein-A seems to be as reliable an indicator for S. aureus of buffalo origin as is coagulase production.