Can adaptive modulation of traits to urban environments facilitate Ricinus communis L. invasiveness?

Abstract

This paper addresses the phenotypic variation among Ricinus communis L. populations in four urban habitat types (road verges, garbage dumps, construction debris, and natural area) in Delhi, India, by evaluating important traits such as plant height, basal circumference, seeds per plant, seed size, seed weight, specific leaf area, and reproductive index. An important biochemical marker, proline, considered as a good plant performance indicator under stress was also quantified in leaves of R. communis to evaluate its response in different habitats. Interestingly, the species showed significant variation in plant height, specific leaf area, seed size, seed weight, and leaf proline content in different habitat types. Leaf proline content was positively related to plant height, specific leaf area, and seed size while negatively related to the total number of seeds/plant. Interestingly, reproductive index, calculated as a ratio of the total number of seeds to the plant height also showed a negative relation with leaf proline content. Results indicated that R. communis exhibits adaptive modulation of growth, reproductive traits, and leaf proline content in various urban habitats which contributes to invasiveness, range expansion, and establishment of the species. The study also gives evidence of how morphological and physiological traits could directly affect invasiveness of R. communis.

Do Plants Have a Choice of Traits to Be Modulated? Evidence from an Invasive Plant <i>Mikania micrantha</i> Kunth in Different Urban Environments

“…Similar kinds of trait modulation in disturbance gradients of urban habitat have been reported in other plants, e.g. Ricinus communis [33] and Calotropis procera [34].…”

“…There are a few studies that have explored trait modulation strategies for individual plants growing in an urban environment in the Indian sub-continent (e.g., Ricinus communis [33], Calotropis procera [34]). Precise locally collected data available from different regions and environments [35], especially for the most serious invaders, would aid in obtaining meaningful results.…”

“…To ensure survivability of seeds, the plants possibly al-located more resources to its reproductive part, as evident from the significantly high amount of reproductive N content. The capacity to produce a large number of seeds at the expense of vegetative structures is one of the key strategies of the invasive species to maintain a steady dynamic population [33].…”

“…The high amount of storage material in the seeds enable seedlings to compete better with superior survivability [33], eventually leading to a significantly high MGT of the seeds. However, despite having the longest duration of germination process, as found in the survival analysis, the probability of having censored seeds is less than 20%.…”

Genetic variation and seed yield in Tunisian castor bean (<em>Ricinus communis</em> L.)

“…LSV exists in two colors, white and dark while the SSV exists mainly in dark color (Akande et al 2012). The study of 12 Indian populations by Goyal et al (2014) shows high phenotypic variation in plant height, specific leaf area, seed size, seed weight, and leaf proline content. Conversely, in Iran, Goodarzi et al (2011) studied genetic diversity on 12 accessions of castor bean, 32 agromorphological traits are analyzed; their result showed low morphological variability.…”