Characterization of Gamma Ray Induced Clones in ‘Giant Cavendish’ Banana (AAA) for Morphological and Yield Contributing Traits

Multiple shoot cultures of ‘Giant Cavendish’ banana cultivar were gamma ray irradiated at 10 Gy and field evaluated for their performance. Among the clones obtained, a semi dwarf variant was selected and multiplied through tissue culture. These clones along with control were established at the Experimental Farm, Kaiga, Karnataka during 2013. Morphological and yield contributing traits showed a wide range of values as compared to the control. Two clones, TBM-2 and TBM-6, were dwarf as against control and late flowering but attained maturity much before the control plants. TBM-8 variant showed substantial increase in the fruit area as against the control. Plant height exhibited negative correlation with number of suckers and fruit circumference while bunch weight showed negative correlation with days to flowering and number of fingers. Cluster analysis based on the Euclidean distances formed three distinct groups. The clones identified in this study have shown the potential of gamma rays in bringing genetic changes in agronomically important traits of banana.     

Chitosan enhances withanolides production in adventitious root cultures of Withania somnifera (L.) Dunal

Calli were obtained from leaf, cotyledon and internode explants of in vitro-grown plants of Indian cultivar of Withania somnifera in MS medium supplemented with 2, 4-D (2.0 mg l⁻¹) and Kinetin (0.2 mg l⁻¹). The brown, semi-friable callus (500 mg FW) derived from leaf explants produced higher number of primary adventitious roots (9 roots/callus) in half strength MS medium fortified with IBA (0.5 mg l⁻¹) and NAA (0.1 mg l⁻¹). The primary adventitious roots with an inoculum mass of 15 g FW were cultured for 6 weeks in the same medium for secondary adventitious root proliferation. Elicitation of abiotic elicitor, aluminium chloride at 10 mg l⁻¹ at the end of 4 weeks culture with 4 h exposure time enhanced withanolides productivity. Under similar culture conditions, the biotic elicitor, chitosan at 100 mg l⁻¹ stimulated higher production of all withanolides when compared to aluminium chloride treatment. This is the first report on the use of callus-derived adventitious root culture for the enhanced production of withanolides upon chitosan elicitation.     

Antioxidant Effect of Dietary Supplement Withania somnifera L. Reduce Blood Glucose Levels in Alloxan-Induced Diabetic Rats

The phenolic compounds and flavonoids were determined from the extracts of Withania somnifera root (WSREt) and leaf (WSLEt). The WSREt has 28.26 mg/g total phenolic compounds and 17.32 mg/g flavonoids, whereas WSLEt has 5.4 mg/g total phenolic compounds and 5.1 mg/g flavonoids. The WSREt, WSLEt and glibenclamide were orally administered daily to diabetic rats for 8 weeks. After the treatment, the levels of urine sugar, blood glucose, liver glycogen, and antioxidants like vitamin C and E in plasma and superoxide dismutase (SOD), catalase (CAT), thiobarbituric acid reactive substances (TBARS), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) in liver, kidney and heart were determined. Diabetic rats showed a significant (p < 0.05) elevation in glucose and TBARS and a significant (p < 0.05) reduction in glycogen, vitamin C and E, SOD, CAT, GPx, GST, and GSH levels when compared to normal control rats. Administration of WSREt, WSLEt and glibenclamide to diabetic rats restored the levels to normal. In the light of aforesaid facts, it is suggested that the presence of phenolic compounds including flavonoids in W. somnifera root and leaf extracts and their antioxidant activity may play a vital role in reduction of blood glucose level in alloxan-induced diabetic rats.     

Selection of efficient arbuscular mycorrhizal fungi in the rhizosphere of cashew and their application in the cashew nursery

Mycorrhizal association in cashew (Anacardium occidentale L.) grown in five different plantation areas of South India was investigated. The soil samples were collected from all locations. Physico-chemical properties of rhizosphere soils, arbuscular mycorrhizal fungal spore count and root colonization were recorded. Species isolated were Acaulospora, Gigaspora, Glomus and Scutellospora. The mycorrhizal spore density was maximum at Thanjavur and minimum at Kudumiyamalai. Root colonization percentage oscillated between 20 and 30%. The species of Glomus, G. aggregatum Schenck and Smith, G. fasciculatum (Thaxter) Gerdemann and Trappe and G. mosseae (Nicol. and Gerd.) Gerdemann and Trappe were the most abundant in the majority of the experimental sites. Hence these three species were selected and used for artificial inoculation studies. Of the three mycorrhizal fungi G. fasciculatum significantly increased shoot length, internode number, internode length, number of leaves, stem diameter, root length and root number.     

High frequency shoot regeneration from cotyledon explants of cucumber via organogenesis

Organogenic callus induction and high frequency shoot regeneration were achieved from cotyledon explants of cucumber. About 86.2% of cotyledon explants derived from 5-day-old in vitro raised seedlings produced green, compact nodular organogenic callus in MS medium containing NAA (2.69 μM) and BA (4.44 μM) after two successive transfers at 20 days interval. Adventitious shoots were produced from the organogenic callus when it was transferred to MS medium supplemented with NAA (1.34 μM), BA (8.88 μM), zeatin (0.91 μM) and l-glutamine (136.85 μM) with shoot induction frequency of 75.6%. Shoot proliferation occurred when callus with emerging shoots was transferred in the same medium at an interval of 20 days. Shoots (1.0 cm length) were excised from callus and were elongated in MS medium fortified with GA₃ (1.44 μM) and BA (4.44 μM). The elongated shoots were rooted in MS medium supplemented with IBA (3.42 μM) and BA (4.44 μM). Rooted plants were acclimatized in green-house and subsequently established in soil with a survival rate of 80%. This protocol yielded an average of 35 shoots per cotyledon explant in a culture duration of 120–140 days.     

Isolation and partial characterization of bacteriophages infecting Vibrio harveyi from shrimp farm effluent water

Bacteriophage isolated from the semi-intensive culture of Pacific white leg shrimp Litopenaeus vannamei infects the luminous bacteria Vibrio harveyi. Lytic activity and lytic spectrum results revealed that the isolated phage had strong lytic activity in V. harveyi, V. parahaemolyticus, and V. vulnificus. Biofilm inhibition activity was performed against different pathogenic vibrios on high-density polyethylene (HDPE) template and the result revealed that the phage effectively inhibited the biofilm formation in V. harveyi. Spectrophotometric assay performed for lytic activity of the isolated phage in V. harveyi liquid culture showed that the phage significantly decreased the V. harveyi cell densities at different time intervals (P?<?0.05). To study the stability of phage at different temperature and pH revealed that the phage withstands the temperature ranged between 40 and 70 °C and the pH of 4 and 9 at a significant level (P?<?0.001). One-step growth curve depicted that the burst size gradually increased to a significant level and reached the maximum of 90% at 180 min (P?<?0.05). This study concluded that the isolated phage had specific activity against pathogenic V. harveyi infections.

     

Potato： A Favorable Crop for Plant Molecular Farming

Molecular farming refers to the production ofrecombinant proteins in heterologous expressionsystems.The recent advances in genomics andproteomics resulted in identification of several newgenes.These have to be functionally characterized toexplore their probable use in diverse applications.Itis quite unlikely that a single expression system couldsupport the production of these proteins,thereforethere is a needtoidentifyandanalyzedifferentnovelex-pression systems for the recombinant protein prod…     

Detection of occurrence of a recent genetic bottleneck event in Indian hill cattle breed Bargur using microsatellite markers

The effective number of breedable individuals is a crucial determinant for maintaining genetic variability within a population. The population of Bargur, the hill cattle of South India, has gone down drastically by more than 93 % in the past three decades, and only a few thousand animals are available at present. The present study was undertaken to evaluate Bargur cattle for mutation drift equilibrium and to detect the occurrence of recent genetic bottleneck event, if any, in this population. About 50 unrelated animals, true to the type, were sampled and genotyped at 25 microsatellite loci. The mean observed heterozygosity (0.808?±?0.023) was higher than the mean expected heterozygosity (0.762?±?0.008) with 15 out of 25 microsatellite loci exhibiting heterozygosity excess when assumed under Hardy–Weinberg equilibrium. To evaluate Bargur cattle for mutation drift equilibrium, three tests were performed under three different mutation models, viz., infinite allele model (IAM), stepwise mutation model (SMM) and two-phase model (TPM). The observed gene diversity (H _e) and expected equilibrium gene diversity (H _eq) were estimated under different models of microsatellite evolution. All the 25 loci were found to exhibit gene diversity excess under IAM and TPM, while 22 loci were having gene diversity excess under SMM. All the three statistical tests, viz., sign test, standardized differences test, and Wilcoxon sign rank test, revealed significant (P?<?0.01) deviation of Bargur cattle population from mutation-drift equilibrium under all the three models of mutation. Furthermore, the qualitative test of allele frequency distribution in Bargur cattle population revealed a strong mode shift from the normal L-shaped form suggesting that the population had experienced genetic bottleneck in the recent past. The occurrence of genetic bottleneck might have led to the loss of several rare alleles in the population, which point towards the need for efforts to conserve this important cattle germplasm. The present study is the first report in demonstrating the genetic basis of demographic bottleneck in an Indian cattle population.     

Evaluation of Four Biodegradable Substrates for Periphyton and Fish Production

Four locally available biodegradable substrates—sugarcane (Saccharum officinales) bagasse, palm (Borasus flabellifera) leaf, coconut (Cocos nucifera) leaf, and bamboo (Bambusa bambos) mat—were evaluated for the production of periphyton and a polyculture of rohu (Labeo rohita) and common carp (Cyprinus carpio) in poultry-manured ponds. Chlorophyll-a, phaeophytin-a, and total pigment content of periphyton were not significantly different (P > 0.05) among substrate types. Dry matter and ash-free dry matter of coconut leaf periphyton were significantly higher (P < 0.05) than that of the other substrates. All four substrates induced significantly (P < 0.05) higher growth, production, and survival of rohu and common carp. Among the substrates used, coconut leaf was more effective in enhancing fish production.     

In vitro propagation of Acacia sinuata (Lour.) Merr. via cotyledonary nodes

Acacia sinuata is a valuable multipurpose tree in Southern India. The tree is over exploited, but its regeneration rate in natural habitat is low. Therefore, it is important to study if it can be regenerated through in vitro micro-propagation. Cotyledonary node and shoot-tip explants excised from 15 day-old in vitro grown seedlings were used to initiate cultures. Maximum number of shoots was induced from cotyledonary node explants on Murashige and Skoog's (MS) medium containing6.66 µM 6-benzylamino purine (BAP) and 4.65µM kinetin (Kn). Subculturing was done in the fresh medium of same composition. The number of shoots formed was comparatively greater in the first subculture. Maximum shoot elongation was achieved (5.5 cm)when subcultured on MS medium supplemented with 1.75 µMgibberellic acid (GA₃). In vitro regenerated shoots produced roots when transferred to half strength MS medium supplemented with 7.36 µM indolebutyric acid (IBA). From each cotyledonarynode 30 shoots were obtained within 90 days after two subcultures. The success rate of establishing the rooted plantlets in the field was 55%.This revised version was published online in November 2005 with corrections to the Cover Date.