Reproductive biology of Withania ashwagandha sp. novo (Solanaceae)

Abstract

Withania ashwagandha Kaul (Solanaceae) is an annual plant species of immense medicinal importance. It is a repository of a large number of pharmacologically active secondary metabolites known as withanolides. Evidence for the delimitation of the species from W. somnifera has been provided by our group using multidisciplinary approaches. Knowledge of reproductive biology of medicinal plants is crucial for improvement, effective conservation and management plans to evolve genetically superior varieties. The present paper reports our findings on the floral biology, pollination behavior and breeding system of W. ashwagandha in natural populations grown at our experimental field under near natural conditions. Flowering (peak) takes place during April-July and anthesis occurs between 08:00 and 11:00 h. The period of stigma receptivity coincides with anther dehiscence. Fruit set on pollination treatments ranged from 90.8% (passive autogamy), 72% (assisted autogamy), 30.30% (xenogamy), and 56.50% (geitonogamy) through 50.40% (open pollination). Xenogamy brings about very low fruit set, seed-set and seed germination percentages. It is inferred that W. ashwagandha is predominantly an autogamous and self-compatible species. Self-compatibility is mainly accomplished due to close proximity of stigma and anthers. This work is the first report on the reproductive biology of W. ashwagandha and will be useful for conservation and development of improved varieties of this multipurpose herb. Highlights► Reproductive biology of W. ashwagandha Kaul was reported first time.► We report the species to be highly self compatible due to close proximity of stigma and anthers.► The period of stigma receptivity coincides with anther dehiscence. ► Fruit set on pollination treatments ranged between 90.8% (passive autogamy) and 30.30% (xenogamy).► Xenogamy brings about very low fruit set, seed-set and seed germination percentages.

Floral Biology Studies in Habanero pepper (Capsicum chinense Jacq.) to Implement in a Cross-Breeding Program

“…In a similar study by Aleemullah et al [18] which analyzed the phenology of Capsicum annuum flowering, it was observed that the anthesis was presented with greater frequency during the morning. In a study of the reproductive biology of Jatropha curcas, Rincón-Rabanales et al [6] found that the flowers, both masculine and feminine, begin to open at 8:00 h, and that the maximum aperture of the flowers is registered at 9:00 h, while Mir et al [5], studying the reproductive biology of Withania ashwagandha sp. Novo (Solanaceae), they observed that the anthesis occurred in an interval between 8:00-11:00 h. These results allow the inference that the more usual anthesis in several species including a Capsicum chinense is that flowers open in the morning.…”

“…Of the three times evaluated (0, 24 and 48 h), the best time for use was the time of harvesting (0 h), given that the pollen presented a greater percentage of viability (88%) and a greater number of seeds per fruit (NSF), although the percentage of fruit set (%FS) was low ( Table 9 and Figure 7). Mir et al [5] concluded that low fructification in cross-pollination after emasculation is an indicator of partial fixation of autogamy in the Withania ashwagandha sp. Novo (Solanaceae).…”

“…A number of studies have been carried out on the floral biology, which include the morphological and reproductive characteristics of genotypes of Acerola (Malpighia emarginata) revised by Gomes et al [3]. In Withania ashwagandha sp., Jatropha curcas, and Moringa oleifera Lam reproductive biology studies have been conducted [4][5][6]. The viability of the pollen and cross-compatibility among various species of Capsicum has been examined [7].…”

Genetic Diversity Analysis in Ashwagandha [Withania somnifera (L.) Dunal] Genotypes

“…Withania somnifera also known as Ashwagandha, Indian ginseng, poison gooseberry or winter cherry belongs to family Solanaceae and is a cross pollinated crop with chromosome number of 2n=48 (Nigam and Kandalkar, 1995) and is one of the important medicinal plants (Mir et al, 2013). It is a hardy and drought tolerant perennial shrub and grows naturally under subtropical dry climate (with an average rain fall of 600-750 mm) in well drained, sandy loam or light red soils that have a pH of 7.5 to 8.0.…”

In vitro propagation and withaferin A production in Withania ashwagandha, a rare medicinal plant of India

“…It is an annual selffertilizing herb with restricted geographic distributed growing exclusively as small-cultivated populations only in drier regions of India (Mir et al 2013). Recently, it has been delineated form wild germplasm of W. somnifera using multidisplinary genome diagnostic approaches (Mir et al 2010;Kumar et al 2011).…”