Chapter 1 INTRODUCTION

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Alicia Taylor
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1 Chapter 1 INTRODUCTION Bamboos with over 70 genera and 1200 species occur worldwide in natural forests, semi-exploited stands, and intensive plantations, covering an area of more than 14 million ha worldwide (Fu and Banik, 1995). The area under bamboo in India has been estimated to be between 3 and 10 million ha (Biswas, 1988 and Fu and Banik, 1995). Bamboos have a long history as a versatile and widely used renewable resource. The range of uses of bamboo for humans is remarkable, with an estimated annual use of 12 kg of bamboo products per capita in Asia (Sastry, 1988). Liese (1992) pointed out that 2.5 billion people depend on or use bamboo worth of US$7 billion per year. It is widely used as fresh edible shoots, culms for timber and raw material for pulping. While supplying products of immediate use to humans, bamboo also serves multiple ecological functions such as soil and water conservation, erosion control (Fu and Banik, 1995). Bamboos have been cultivated in villages, and the rural poor are the principal users of bamboo (Banik, 1996). Farmers preferably cultivate bamboo species to fulfill their social, ecological and economical needs (Nath and Das, 2008). India s current demand for bamboo is estimated at 27 million tones to meet all the industrial and domestic requirements. However, only 50 percent of that demand can be met, the gap can be possibly reduced by undertaking large scale plantations of bamboo with qualities that can meet specific industrial and commercial requirement. D. stocksii is one of the 18 economically important bamboo species identified for its industrial and economic value and being recommended for large scale cultivation in peninsular India by National Bamboo Mission. Dendrocalamus stocksii (Munro), synonym Oxytenanthera stocksii / Pseudoxytenanthera stocksii is naturally distributed in Western Ghats. D. stocksii is locally known as Manga in Maharashtra; Shime-bidaru, Marihal bamboo in Karnataka; Kondya in Goa. D. Stocksii has medium sized, solid and strong culms. A Culm attains a height of m with basal diameter of cm and internode length of cm. This species is endemic to Western Ghats of India (12 o to 17.5 o North latitudes). D. stocksii is cultivated in the coastal belts of Karnataka (Seethalakshmi and Mukteshkumar, 1998). It is a widely domesticated species, usually incorporated in field 12

2 bunds/farm boundaries and in homesteads (Viswanath et al., 2013). Its distribution is mostly confined to the banks of streams as it requires well drained deep soil and is primarily planted around the arecanut gardens and paddy fields (Dewar, 2000). Lastly National Bamboo Mission has prioritized this species for mass scale cultivation in Maharashtra and Karnataka (Haridasan and Tiwari, 2008). D. stocksii is an extremely manageable bamboo species with great economic and ecological importance (Singhal and Gangopadhyay, 1999) finding large scale utilization in scaffolding, paper and pulp, crafts, construction, basket making, umbrella handles and poles. Culms of this species are thronless with non-prominent nodes and better culm wall thickness to culm diameter ratio (cw/cd), hence, it is best bamboo species in the below two inch category for construction and furniture industry (Viswanath et al., 2013). In recent past, its application has increased in luxury products like sofa sets, dining table, resort structures, bamboo house etc. So also there is an upcoming demand in the agricultural sector to construct bamboo green house and farm structures. These new emerging sectors add value to this species. However, the industrial potential of this species can only be increased if its culm diameter is increased beyond 50 mm with ratio of culm wall thickness to culm diameter of 1:3. So also, the bamboos specifically required for furniture should be straight and upright stem, small tapering and smooth nodes for furniture framework processing. The bamboo culms should have thicker walls, and be tenancious enough, the age of selected bamboo should be 3-4 years (INBAR, 2001). Hence, in order to increase the end use potential of this species, it is required to understand the diversity present in this species along the area of its distribution. The amount of genetic variation available within species determines the potential for improving the species through breeding programs (Wright et al., 2007). Mating influences the movement of genes in space and their transmission through time. It therefore plays a fundamental role in determining the spatial and temporal patterns of genetic diversity within and between populations and their evolutionary dynamics (Barret, 2003). Monoecy and protogyny are widespread in wind-pollinated plants and have been interpreted as outcrossing mechanisms (Friedman and Barret, 2009).The studies on reproductive biology of D. stocksii reveal that, the spikelets are bisexual, dichogamous and protogynous in nature (Beena et al., 2007). The species is predominantly cross pollinating because of a long duration of 3-4 days between female and male phase ensuring supply of pollen from other flowers. It is observed that 13

3 gynoecium matures 3-4 days before androceium (protogyny), thus preventing self pollination. But the species does not produce seeds (Seethalakshmi and Mukteshkumar, 1998) because of quick drying of anthers and lack of dehiscence and pollen deposition on stigmatic hairs. However, non-seeding behavior of a bamboo species does not have any influence on intraspecific diversity of a species, as was observed in Bambusa vulgaris (Otonet al., 2006), which showed a better dissimilarity index among the individuals. Hence, distribution and diversity of Dendrocalamus stocksii along the Western Ghats in the absence of true seed is of interest from the evolution point of view. Species variation is an essential component in the development and evolution of living creatures. Patterns of variation within tree species depend on several factors, including geographic distribution, breeding system and historical events. The latter may include range fragmentation associated with climatic and landscape instability and changes in effective population, which are strong determinants of population genetic structure (Ahida et al. 2006). Environment has long been recognized as a key determinant of plants phenotype through effects on survival, growth and reproduction and in the longer term, through acting as a major selection force affecting plant genotype. Climate-related natural selection leads to local adaptation and differentiation of tree populations along climatic gradients (Howe et al., 2003). Thus, tree populations typically show moderate to strong local adaptation despite high levels of gene flow (Howe et al., 2003, Savolainen et al., 2007). Selection effects and niche partitioning are two mechanisms that account for non-additive diversity effects, and both rely on functional differences among genotypes (or species) in productivity or resource use, respectively (Cardinaleet al., 2007).Through examination of provenances for more than 100 years by countries all over the world, has confirmed that most species exhibit geographic variation, among different provenances (Cun-ji et al., 2002). This has played a very important role in selecting fine provenances and gaining significant genetic strength. Phenotypes are determined by genotypes and by the environmental conditions under which individuals live (Wang et al., 2009). Variability exists for culm morphological characters among the individuals of a bamboo species (Lewis et al., 2010; Battacharya et al., 2006; Singh et al., 2004; Niwedita et al., 2001). A clear understanding of the degree of divergence for economic characters in the species will be an added advantage in this regard, as inter-mating of divergent groups would increase variability and range of frequency distribution (Alicchio and Palenzona, 1974). 14

4 Estimation of genetic divergence has wide scope in tree breeding as it helps in identifying the diverse genotypes for a crossing programme (Pandeyet al., 1995 and Tewariet al., 1989). It is observed that among the culm characteristics, culm biomass, culm diameter, internode length, leaf length and culm height have high genotypic coefficient of variation and heritability coupled with better genetic advance values and will respond effectively on phenotypic selection (Singh et al., 2004). Bamboo also shows variation in physiological parameters like photosynthetic rates between different ages of culm, season and location (Volker and Midmore, 2001). Significant differences among populations have been reported in growth and physiological properties that govern the performance of the species under given environmental conditions. Variations in net photosynthesis, stomatal size and density have been reported as determinants of plant productivity (Luukkanen and Kozolowshi, 1972, Pallardy and Kozlowski, 1979, Wang et al, 1995). For long time there have been considerable efforts to elucidate the degree and nature of the genetic control over Water Use Efficiency (WUE) (Zhang et al., 2004). Net photosynthesis and related gas exchange parameters have been suggested as early selection criteria to improve the efficiency of tree breeding (Lapido et al. 1984, Ceulemans et al, 1984) Phenotypic variations are usually validated through variations at genetic level. Molecular DNA techniques allow researchers to assess the relative diversity within and among the species and locate diverse accessions for breeding purposes. The genetic variation and differentiation among the bamboo species is established by adopting molecular marker approaches, including RAPD (Random Amplified Polymorphic DNA) (Das et al., 2005), SSRs (Simple Sequence Repeats) (Sharma et al., 2008) and ISSRs (Inter-Simple Sequence Repeats) (Lin, et al., 2009). Among them, ISSR technique is easily applied, identifies high polymorphism and displays acceptable reproducibility and widely used in population genetics studies (Yang, 2012).The use of inter-simple sequence repeats (ISSR) has been reported more useful for assessing genetic diversity in plant populations and inferring genetic relationships among closely related cultivars compared to standard DNA sequencing methods. In bamboo, the most important and practical application at present is undoubtedly the precise identification of bamboo genotypes and assessment of genetic variation within species (Gieles, et al., 1995). The economic potential of this species is immense coupled with a wide scope for value addition. D. stocksii is a widely accepted 15

5 bamboo species by the farmers along the Central Western Ghats. Its distribution is on leeward and windward side of the Western Ghats and is exclusively maintained on private lands outside the forests. This distribution pattern across the Central part of Western Ghats is mediated by anthropogenic factors. Further, it has been obligatorily propagated through vegetative means, may be after a process of primary selections by the farmers. Varying environmental conditions across the various land use systems might have dictated the adaptive behavior of this species. Further, presence of sporadic and gregarious flowering coupled with cross pollination in this species might have facilitated cross pollination and created natural diversity in this species. A study was necessary to understand how this species is distributed across the ecologically diversified Western Ghats on one hand and its adaptive behavior towards a particular niche on the other. Precisely, the knowledge of a Germplasm from an extreme location will physiologically behave under differnet environment can help in selecting populations for physiological adaptability. Lastly, a clear understanding of the genetics behind its entire variation and patternof distribution of this species is necessary, hence a study was undertaken with the following three objectives 1. To study the geographic variation in relation to culm and clump characteristics of D. stocksii in Western Ghats. 2. To evaluate the representative clumps from different geographic locations of Western Ghats for their physiological properties. 3. To assess the genetic diversity of selected populations of D. stocksii through ISSR marker. 16

IUCN Red List Process. Cormack Gates Keith Aune

IUCN Red List Process. Cormack Gates Keith Aune IUCN Red List Process Cormack Gates Keith Aune The IUCN Red List Categories and Criteria have several specific aims to provide a system that can be applied consistently by different people; to improve