12 research outputs found

    Syzygium (Myrtaceae): Monographing a taxonomic giant via 22 coordinated regional revisions

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    Syzygium Gaertn. is the largest woody genus of flowering plants in the world. Unpublished but extensive recent herbarium surveys suggest 1200‒1800 species distributed throughout the Old-World tropics and subtropics (Table 1). Until recently, Syzygium exemplified a recurring taxonomic impediment among megadiverse genera, wherein few taxonomists worked on the group in any sustained manner, a majority of the herbarium specimens remained undetermined or misidentified, few if any attempts were made to look at the genus globally and limited or no molecular studies were available to provide a predictive phylogenetic context of the genus. The situation with Syzygium has slowly begun to change as allied genera have been absorbed into the genus (Biffin et al., 2006; Craven & Biffin, 2010), and predictive phylogenetically based infrageneric classifications are emerging. Taxonomic outputs on Syzygium also have been increasing across its range with the description of new species, resolution of nomenclatural and typification issues, and some regional revisions being initiated or updated. However, virtually all regional treatments (which some areas lack) need urgent revision because they are severely outdated, have limited molecular sampling and are error-ridden. We are coordinating a genus-wide taxonomic update of Syzygium through a series of 22 regional revisions, including 9 in the Flora Malesiana region (Figure 1). Each treatment will include a phylogenetic framework with species descriptions, type information, synonymy, distributions, ecological notes, and keys. Field images (Figure 2) and/or line drawings will be included with the goal of every species being illustrated. This working group has been formed to encourage a coordinated effort to document this unwieldy taxonomic giant and regional botanists working on the group are encouraged to be involved. A robust taxonomy of the genus is a prerequisite for testing the many complex questions about evolution and ecology that Syzygium could help address

    The Birth of Aus Agriculture in the South-eastern Highlands of India – an Exploratory Synthesis

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    Away from the Ganges valley, the south-eastern highlands of India is recognized as the region of origin of upland or 'aus' rice. In this narrative, we attempt to reconstruct its origin synthesizing inklings from genetics, prehistory, and anthropology, and to find out the putative paleo-ecological, environmental, and cultural context that provided the necessary impetus to it. Genetically, we uncover a highly diverse phenotypic base with unique alleles hinting at an independent origin of 'aus' perhaps from 'Oryza nivara'. Post-LGM paleo-niche portrays more widely distributed 'O. nivara' as opposed to 'O. rufipogon'; relatively abundant 'O. nivara' could have enabled its preferential exploitation. While a dearth of archaeological study does not illuminate much on this aspect; the agricultural attributes of the ethnic inhabitants of the area, e.g., dry rice cultivation with the hoe and the axe, reveal a striking similarity with 'aus' or upland rice cultivation. Furthermore, comparative analyses with other historical anecdotes suggest that upland rice seems to be born as an adaptive landscape management by pre-agriculturist society. It was developed through a broader plant-people-landscape interaction, where rice or its ancestors were grown for subsistence with other crops as a Neolithic proto-agricultural package; in this case along the hill slopes. Summarizing, the current study casts light on some of the understudied aspects of upland rice agriculture, but it also brings out many open questions inviting future examination

    Rapid divergence of ecotypes of an invasive plant

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    Invasive species demonstrate rapid evolution within a very short period of time allowing one to understand the underlying mechanism(s). Lantana camara, a highly invasive plant of the tropics and subtropics, has expanded its range and successfully established itself almost throughout India. In order to uncover the processes governing the invasion dynamics, 218 individuals from various locations across India were characterized with six microsatellites. By integrating genetic data with niche modelling, we examined the effect of drift and environmental selection on genetic divergence. We found multiple genetic clusters that were non-randomly distributed across space. Spatial autocorrelation revealed a strong fine-scale structure, i.e. isolation by distance. In addition, we obtained evidence of inhibitory effects of selection on gene flow, i.e. isolation by environmental distance. Perhaps, local adaptation in response to selection is offsetting gene flow and causing the populations to diverge. Niche models suggested that temperature and precipitation play a major role in the observed spatial distribution of this plant. Based on a non-random distribution of clusters, unequal gene flow among them and different bioclimatic niche requirements, we concluded that the emergence of ecotypes represented by two genetic clusters is underway. They may be locally adapted to specific climatic conditions, and perhaps at the very early stages of ecological divergence

    Phenotypic characters of rice landraces reveal independent lineages of short-grain aromatic indica rice

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    Rice landraces are lineages developed by farmers through artificial selection during the long-term domestication process. Despite huge potential for crop improvement, they are largely understudied in India. Here, we analyse a suite of phenotypic characters from large numbers of Indian landraces comprised of both aromatic and non-aromatic varieties. Our primary aim was to investigate the major determinants of diversity, the strength of segregation among aromatic and non-aromatic landraces as well as that within aromatic landraces. Using principal component analysis, we found that grain length, width and weight, panicle weight and leaf length have the most substantial contribution. Discriminant analysis can effectively distinguish the majority of aromatic from non-aromatic landraces. More interestingly, within aromatic landraces long-grain traditional Basmati and short-grain non-Basmati aromatics remain morphologically well differentiated. The present research emphasizes the general patterns of phenotypic diversity and finds out the most important characters. It also confirms the existence of very unique short-grain aromatic landraces, perhaps carrying signatures of independent origin of an additional aroma quantitative trait locus in the indica group, unlike introgression of specific alleles of the BADH2 gene from the japonica group as in Basmati. We presume that this parallel origin and evolution of aroma in short-grain indica landraces are linked to the long history of rice domestication that involved inheritance of several traits from Oryza nivara, in addition to O. rufipogon. We conclude with a note that the insights from the phenotypic analysis essentially comprise the first part, which will likely be validated with subsequent molecular analysis

    Predictive distribution modeling for rare Himalayan medicinal plant Berberis aristata DC

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    Predictive distribution modelling of Berberis aristata DC, a rare threatened plant with high medicinal values has been done with an aim to understand its potential distribution zones in Indian Himalayan region. Bioclimatic and topographic variables were used to develop the distribution model with the help of three different algorithms viz. GeneticAlgorithm for Rule-set Production (GARP), Bioclim and Maximum entroys(MaxEnt). Maximum entropy has predicted wider potential distribution (10.36%) compared to GARP (4.63%) and Bioclim (2.44%). Validation confirms that these outputs are comparable to the present distribution pattern of the B. atistata. This exercise highlights that this species favours Western Himalaya. However, GARP and MaxEnt's prediction of Eastern Himalayan states (i.e. Arunachal Pradesh, Nagaland and Manipur) are also identified as potential occurrence places require further exploration

    Hydrological importance of sacred forest fragments in Central Western Ghats of India

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    Sacred groves are patches of forests of special spiritual significance to humans, offering also a diverse range of ecological and environmental services. We have attempted here to understand the local hydrological dynamics of a sacred forest, in terms of the benefits the village community derive, in central Western Ghats region of India. A comparative assessment has been made between two small watersheds in terms of their landscape structure (woody species composition) with soil water properties and availability of water in the respective downstream villages. The result shows that, sacred site with more primeval vegetation has close association with soil moisture in comparison to non-sacred site during dry spell of the year. The higher soil moisture ensures year long availability of water in the downstream village of the sacred site which facilitates farming of commercial crops with higher economic returns to the farmers, unlike the farmers in the other village where they face water crisis during the lean season. The study emphasizes the need for conservation endeavour on sacred groves highlighting its potential for water conservation at local and regional levels

    Socio-cultural protection of endemic trees in humanised landscape

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    Culturally protected forest patches or sacred groves have been the integral part of many traditional societies. This age old tradition is a classic instance of community driven nature conservation sheltering native biodiversity and supporting various ecosystem functions particularly hydrology. The current work in Central Western Ghats of Karnataka, India, highlights that even small sacred groves amidst humanised landscapes serve as tiny islands of biodiversity, especially of rare and endemic species. Temporal analysis of landuse dynamics reveals the changing pattern of the studied landscape. There is fast reduction of forest cover (15.14-11.02 %) in last 20 years to meet up the demand of agricultural land and plantation programs. A thorough survey and assessment of woody endemic species distribution in the 25 km(2) study area documented presence of 19 endemic species. The distribution of these species is highly skewed towards the culturally protected patches in comparison to other land use elements. It is found that, among the 19 woody endemic species, those with greater ecological amplitude are widely distributed in the studied landscape in groves as well as other land use forms whereas, natural population of the sensitive endemics are very much restricted in the sacred grove fragments. The recent degradation in the sacred grove system is perhaps, due to weakening of traditional belief systems and associated laxity in grove protection leading to biotic disturbances. Revitalisation of traditional practices related to conservation of sacred groves can go a long way in strengthening natural ecological systems of fragile humid tropical landscape

    Harmony ideology revisited: spatial geographies of hegemony and disputing strategies amongst the Santal

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    In her book Harmony ideology Laura Nader demonstrates that dispute resolution practices within minority ethnically distinct communities may serve not only a quasi-legal, but also a political, hegemonic, function. National governance structures and relations between the state and non-state entities provide a critical context for understanding dispute resolution practices within such communities. This paper examines how the historical legal and social ‘othering’ of a tribal minority, the Santal, in India and Bangladesh has created two opposing counter-hegemonic strategies, manifest in the people’s dispute resolution practices. The paper begins by exploring the historical backdrop of the Santal’s exclusion and subordination in the two countries. The paper then examines disputing strategies to assess how dispute processes act as a mirror reflecting back this exclusion, reforming the nuances of separation as a symbol of defiance. My fieldwork data shows that strategies of disputing are closely linked with the spatial proximity of and perceived locality of oppression. Inward looking strategies that promote harmony and re-enforce minority hegemonies act as strategies of resistance where an oppressor takes the form of a distant and untouchable state or power elite. But where the politics of struggle is local and immediate disputing turns outward and confrontation replaces harmony as a counter-hegemonic strategy
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