Floral Phenology of Chlorophytum arundinaceum Baker in Subtropical Climes of Jammu

2020 ◽  
Vol 36 (1-2) ◽  
pp. 245-248
Author(s):  
Renuka Kumari ◽  
◽  
Mamata Jamwal ◽  
Namrata Sharma ◽  
◽  
...  
Keyword(s):  
1996 ◽  
Vol 135 (1) ◽  
pp. 144 ◽  
Author(s):  
Mark A. Schlessman ◽  
Nora C. Underwood ◽  
Laura M. Graceffa
Keyword(s):  

Petersianthus macrocarpus is a plant species whose pollens are potentially allergenic. This plant is present from the coast to the centre of the country. The objective of this study is to prevent populations from being exposed to the pollens of Petersianthus macrocarpus. Specifically, it was a question of defining the flowering of Petersianthus macrocarpus, evaluating the impact of the climate on this flowering and listing the populations most exposed to P. macrocarpus pollens. The study took place in Abidjan, in the commune of Yopougon, specifically in South Niangon, from September 2017 to June 2020. Sampling by quadrat allowed to determine the number of individuals, the cover, the density and the frequency of the vegetation. Floral phenology was carried out by weekly observations using binoculars. The coverage in each quadrat was 1 and the frequency 100%. Individuals less than 6 m high did not bear any flowers. Two flowering periods were observed in the years 2017 to 2019. The first was from April to June, the second from November to January. However, there was no flowering from April to June in 2020. The evolution of rainfall in 2020 was not identical to that of the three previous years. The phenology of Petersianthus macrocarpus presents periods of high risk of pollinosis and is influenced by rainfall. Increasing wind speed exposes new populations to pollen. The installation of pollen collectors is certainly necessary to establish the pollen calendar of Petersianthus macrocarpus in Côte d’Ivoire.


Sociobiology ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 173
Author(s):  
Bruno De Sousa-Lopes ◽  
Eduardo Soares Calixto ◽  
Eduardo Soares Calixto ◽  
Helena Maura Torezan-Silingardi ◽  
Helena Maura Torezan-Silingardi ◽  
...  

Besides the eff ectiveness of floral visitors, to better understand pollination systems is necessary to consider the role of predators. Ants are ubiquitous on the vegetation, especially on plants bearing extrafloral (EFNs) and pericarpial nectaries (PNs). Both EFNs and PNs reward ants which in turn provide to plants effective protection against herbivores. However, ants can also repel pollinators and cause an indirect cost for the plant partner, although the role of ants on pollinators’ performance has rarely been assessed in Neotropics, mainly on PN-bearing plants. Here, our main aim was, through an experimental field study in terms of ant’s presence versus absence, to test the hypothesis that ants dissuade floral visitors by decreasing the time spent during visits on the PN-bearing Declieuxia fruticosa. Additionally, we recorded floral phenology, and quantified and qualified floral visits. We showed that bees were the most frequent pollinators and the presence of ants dissuades them. In ant presence, pollinators were on average 30% faster than without ants. Since D. fruticosa produces fruits mainly after cross-pollination, the role of ants may be profi table to plants as they induce pollinators to do shorter visits and search for other fl owers in conspecifi c plants. Therefore, pollinators avoid stay at longer on plants with ants in order to avoid attacks, which may contribute to plant outcrossing. However, whether positive or negative the effects of ants on D. fruticosa reproduction are, they remain to be studied.


2004 ◽  
Vol 52 (2) ◽  
pp. 185 ◽  
Author(s):  
David H. Duncan ◽  
Saul A. Cunningham ◽  
Adrienne B. Nicotra

We used pollinator observation, flower manipulation, controlled pollination and pollen-tube analysis to better understand the reproductive ecology of Dianella revoluta R.Br., a common species known to have depressed fruit set at fragmented sites. This buzz-pollinated species was found to receive large quantities of self-pollen even during a single pollinator visit, but is only partially self-compatible. This may be the first direct demonstration of pollinator-facilitated, autogamous self-pollen transfer accounting for a significant proportion of stigmatic pollen load. Frequent high self-pollen transfer may account for the observed low rate of fruit development in open-pollinated flowers. Self-pollen tubes reached the base of the style in comparable numbers and at the same rate as outcross pollen tubes, with no sign of pollen-tube competition favouring outcross pollen. Barriers to greater self-fertility occur late, probably through early abortion of selfed ovules. We also investigated what impact overlapping distribution with D. longifolia may have on D. revoluta pollination and reproduction. Although these species shared pollinators, they differed in terms of frequency of visits. There was also separation of floral phenology within the course of a day.


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