R. Vasudeva

Endophytic fungal strains of Fusarium solani, from Apodytes dimidiata E. Mey. ex Arn (Icacinaceae) produce camptothecin, 10-hydroxycamptothecin and 9-methoxycamptothecin

Camptothecin and 10-hydroxycamptothecin are two important precursors for the synthesis of the clinically useful anticancer drugs, topotecan and irinotecan. In recent years, efforts have been made to identify novel plant and endophytic fungal sources of camptothecin and 10-hydroxycamptothecin. In this study we have isolated endophytic fungi strains from Apodytes dimidiata (Icacinaceae), a medium sized tree from the Western Ghats, India. The fungi were identified as Fusarium solani using both ITS rDNA sequencing and spore morphology. Two strains, MTCC 9667 and MTCC 9668 were isolated, both of which produced camptothecin and 9-methoxycamptothecin in their mycelia; one of the strains, MTCC 9668 also produced 10-hydroxycamptothecin, though in small amounts. The yields of camptothecin in MTCC 9667 and MTCC 9668 were 37 and 53 microg/100g, respectively, after 4 days of incubation in broth culture. The yields of 10-hydroxycamptothecin and 9-methoxycamptothecin in MTCC 9668 were 8.2 and 44.9 microg/100g, respectively. Further research in optimizing the culture conditions of these fungal strains might permit their application for the production of camptothecin and 10-hydroxycamptothecin.

Evolution of style-length variability in figs and optimization of ovipositor length in their pollinator wasps: A coevolutionary model

Monoecious figs reward their pollinators—agaonid wasps—by allocating a proportion of the flowers for egg laying, and retain the rest for seed production. It has been suggested that these proportions could be regulated by producing short-styled and long-styled flowers such that pollinator wasps could only use the former as their ovipositor does not reach the ovules of the latter. Thus the wasps can lay eggs only in the short-styled flowers and raise their offspring, and the ovules of uninfested, long-styled flowers can develop into seeds. This implied that figs bear dimorphic female flowers, with a bimodal distribution of style length. However, recent studies have shown that style length is distributed normally, with no evidence of bimodality. Therefore the regulation of allocation of flowers to the wasps does not seem to be through the production of two distinct kinds of female flowers. In this article we suggest that two factors govern the proportion of flowers rewarded to the wasps: (i) passive regulation, which is a consequence of the optimization of wasp ovipositor length, and (ii) active regulation, where figs are selected to enhance the variance of style length. We show that these arguments lead to certain predictions about the optimum ovipositor length, the proportion of the flowers available to the wasps, and the coefficient of variation of style length. We also show that data for 18 fig-wasp associations conform well with these predictions. We finally suggest that the regulatory process outlined here can be extended to evolution of style length in dioecious fig species also.

Chemical Profiling of Nothapodytes nimmoniana for Camptothecin, an Important Anticancer Alkaloid: Towards the Development of a Sustainable Production System

Camptothecin (CPT), a pyrrolo quinoline alkaloid, is one of the most promising anticancer drugs of the 21st century. The compound was first isolated from the Chinese deciduous tree, Camptotheca acuminata. CPT exhibits a broad spectrum of antitumor activity both under in vitro and in vivo conditions. Irinotecan (CPT11) and Topotecan (TPT), two water-soluble derivatives of CPT, have been approved by the United States Food and Drug Administration for treating colorectal and ovarian cancers as well as against several types of brain tumor in children. Although CPT has been reported to exist in several species, the highest concentration (about 0.3 %) to date has been realized from Nothapodytes nimmoniana. The tree commonly referred to as “stinking tree” is native to warmer regions of South India. In the last few decades, driven by the enormous demand for CPT, there has been a decline of at least 20 % in the population, leading to red listing of the species. In recent years, efforts have been initiated in India to identify high-yielding individuals and populations of N. nimmoniana in its natural distribution range with the ultimate aim of using these lines to develop clonal orchards, as well as in developing in vitro production systems.In this chapter, we briefly review the overall status of N. nimmoniana as a source of CPT. Drawing upon existing literature as well as ongoing work at our laboratory, we discuss the basic patterns of accumulation of CPT in N. nimmoniana. We review the population variability for CPT accumulation along the distributional range of the species in the Western Ghats, India. Using a relatively new tool, namely the ecological niche model, we predict the chemical hot-spots of the species in the Western Ghats and offer a test of this prediction. Finally, we discuss strategies for a sustainable model of extraction of CPT from N. nimmoniana.

Changes in genetic diversity parameters in unimproved and improved populations of teak (Tectona grandis L.f.) in Karnataka state, India

Teak (Tectona grandis L. f.; family Verbanaceae) is an important plantation tree species in the tropics and in India one of the first species to be prioritized for improvement. Improvement efforts for the last 50 years have essentially concentrated on augmenting quality seed production by establishing seed production areas (SPA) and clonal seed orchards (CSO). Presently, these two form the main sources of quality planting material for teak throughout the country. However, there is no information on the genetic quality of such sources nor information on the progeny used in plantation programmes. Reports of studies based on coniferous and tropical species provide conflicting results on the impact of domestication on the genetic diversity of populations (Chaisurisri and El Kassaby 1994; Rajora 1999; Moran et al. 2000; Godt et al. 2001; Icgen et al. 2006). Also the impact of domestication on the genetic diversity of progeny populations is poorly understood (Stoehr and El-Kassaby 1997; Schmitdtling and Hiplins 1998). Such studies become pertinent not only for gauging the impact of selection on reforestation stock, but also for effective genetic conservation of existing breeding populations. We therefore address two issues in the present study: (i) the change in genetic diversity with increasing levels of improvement, and (ii) the impact of the above change on genetic diversity of progeny populations.

Influence of geographic distance and genetic dissimilarity among clones on flowering synchrony in a Teak (Tectona grandis Linn. f) clonal seed orchard

Abstract Influence of genetic dissimilarity among teak (Tectona grandis Linn. f.) clones on flowering synchrony was studied in a Clonal Seed Orchard (CSO) of teak in Karnataka, Southern India. Flowering phenology was monitored for all the 24 teak clones of the CSO and flowering synchrony between clones was assessed adopting a novel ‘overlap index’. Genetic dissimilarity among these clones was assessed adopting DNA based ISSR (Inter Simple Sequence Repeats) analysis. Large variation in the time of ‘flower initiation’ and of ‘peak flowering initiation’ was observed among the clones belonging to diverse sources, suggesting large asynchronous flowering. Cluster analysis based on ISSR marker indicated that the clones originating from a same source clustered together and there was a clear segregation based on their origin. Correlation analysis revealed a significant negative association between the average Jaccards’s dissimilarity index between pairs of clones and average peak flowering overlap index. Clones from geographically diverse regions had high genetic dissimilarity and also showed high flowering asynchrony within them.

Identification of novel microsatellite markers for Saraca asoca, a medicinally important tree species in India

1Conservation Genetics, Ashoka Trust for Research in Ecology and the Environment, Royal Enclave, Srirampura, Jakkur Post, Bangalore 560 064, India 2School of Ecology and Conservation, 3Department of Crop Physiology, University of Agricultural Sciences, GKVK Campus, Bangalore 560 065, India 4Biology Department, Concordia University, 7141, Sherbrooke Street West, Montreal, Canada H4B1R6 5Department of Forest Biology and Tree Improvement, College of Forestry, University of Agricultural Sciences, SIRSI campus, Dharwad 581 401, India

Development and characterization of microsatellite markers for Dysoxylum binectariferum, a medicinally important tree species in Western Ghats, India.

1Ashoka Trust for Research in Ecology and the Environment, Royal Enclave, Srirampura, Jakkur Post, Bangalore 560 064, India 2School of Ecology and Conservation, University of Agricultural Sciences, GKVK Campus, Bangalore 560 065, India 3Department of Crop Physiology, University of Agricultural Sciences, GKVK Campus, Bangalore 560 065, India 4Department of Forest Biology and Tree Improvement, College of Forestry, University of Agricultural Sciences, SIRSI campus, Dharwad 581 401, India

Development of eleven microsatellite markers in the red-listed tree species Myristica malabarica

The Myristicaceae family is a primitive angiosperm family and is characterized by species that are highly endemic to the Western Ghats area of India. Myristica malabarica is confined to the evergreen forests of Western Ghats and Sri Lanka. In this paper we describe for the first time the development of eleven polymorhpic microsatellite markers for Myristica malabarica, which had 2–14 alleles per locus. These microsatellite markers could be used to study the population genetic structure of the species.

Isolation and characterization of microsatellite markers in Garcinia gummi-gutta by next-generation sequencing and cross-species amplification

Garcinia gummi-gutta (L.) Roxb. (Clusiaceae) is an endemic, semidomesticated, fruit-yielding tree species distributed in the Western Ghats of India and Sri Lanka. Various bioactive phytochemicals, such as garcinol, benzophenones and xanthones are isolated from G. gummi-gutta and have shown antibacterial, antiviral and antioxidant activities. We sequenced the total genomic DNA using Illumina Hiseq 2000 platform and examined 241,141,804 bp high quality data, assembled into 773,889 contigs. In these contigs, 27,313 simple-sequence repeats (SSRs) were identified, among which mononucleotide repeats were predominant (44.98%) followed by dinucleotide and trinucleotide repeats. Primers were designed for 9964 microsatellites among which 32 randomly selected SSR primer pairs were standardized for amplification. Polymerase chain reaction (PCR) amplification of genomic DNA in 30 G. gummi-gutta genotypes revealed polymorphic information content (PIC) across all 32 loci ranging from 0.867 to 0.951, with a mean value of 0.917. The observed and expected heterozygosity ranged from 0.00 to 0.63 and 0.896 to 0.974, respectively. Alleles per locus ranged from 12 to 27. This is the first report on the development of genomic SSR markers in G. gummi-gutta using next-generation sequencing technology. The genomic SSR markers developed in this study will be useful in identification, mapping, diversity and breeding studies.

Authentication of Garcinia fruits and food supplements using DNA barcoding and NMR spectroscopy

Garcinia L. (Clusiaceae) fruits are a rich source of (−)-hydroxycitric acid, and this has gained considerable attention as an anti-obesity agent and a popular weight loss food supplement. In this study, we assessed adulteration of morphologically similar samples of Garcinia using DNA barcoding, and used NMR to quantify the content of (−)-hydroxycitric acid and (−)-hydroxycitric acid lactone in raw herbal drugs and Garcinia food supplements. DNA barcoding revealed that mostly G. gummi-gutta (previously known as G. cambogia) and G. indica were traded in Indian herbal markets, and there was no adulteration. The content of (−)-hydroxycitric acid and (−)-hydroxycitric acid lactone in the two species varied from 1.7% to 16.3%, and 3.5% to 20.7% respectively. Analysis of ten Garcinia food supplements revealed a large variation in the content of (−)-hydroxycitric acid, from 29 mg (4.6%) to 289 mg (50.6%) content per capsule or tablet. Only one product contained quantifiable amounts of (−)-hydroxycitric acid lactone. Furthermore the study demonstrates that DNA barcoding and NMR could be effectively used as a regulatory tool to authenticate Garcinia fruit rinds and food supplements.