Morphophysiological investigations in some dominant alien invasive weeds

Abstract

The campus of the University of Pune represents a unique deciduous forest ecosystem as it is highly dominated by an introduced shrub Dalbergia melanoxylon Guill. This campus shows rich herbaceous phytodiversity of native and invasive plants. At present most of the alien weeds are suppressing the native diversity. The morphological and ecophysiological studies clearly revealed their faster growth and biomass production rate, very high reproductive abilities and tolerance to different biotic and abiotic stresses leading to successful invasions. This might be ascribed to their richness in different types of allelochemicals like triterpenes, phenols, steroids, flavonoids bitter principles along with the osmolytes like proline, glycine betaine. This subsequently creates an inhospitable environment to native plants and threatens their survival causing an inception of biodiversity losses. The present attempt may provide some clues to understand the mechanism of their invasion and dominance.

Morphophysiological Investigations in Some Dominant Alien Invasive Weeds

“…More accumulation of antioxidants and stimulated activities of antioxidant enzymes might be becoming helpful for stress tolerance to these weeds. The results of the present investigations are in agreement with the findings of Bhalerao (2003), Jadhav (2006), Vaidya (2009) andGhayal et al (2009). They have also reported comparatively higher stimulation of antioxidant enzymes like PPO, POX and SOD in some invasive as well as native weeds of forest, aquatic and terrestrial ecosystems.…”

“…The results recorded on photosynthetic pigments in different invasive and native weeds were corroborating with that of photosynthetic rate and other gas exchange parameters (Table 4 and Figure 1). Ghayal et al (2009) Photosynthetic pigments are the master molecules in carbon assimilation process, which govern photosynthetic efficiency. Sampietro et al (2007) explained that the growth, development, dominance and allelopathic potential of any plant species mostly depend on its physiological, biochemical and enzymological characteristics.…”

Growth and mycorrhizal colonization of maize plants treated with aqueous extracts from nonmycorrhizal weeds

“…In addition, it is possible that the allelochemicals present in the slender amaranth extract interfered in basic plant processes, such as hormonal balance and respiration, among others, and altered the growth of AM plants by direct or indirect mechanisms (Bogatek & Gniazdowska, 2007;Ghayal et al, 2009), which include their interaction with the symbiotic fungus Cetraspora pellucida.…”