Some biological aspects of the weed Lesser celandine (Ranunculus ficaria)

Abstract

-Lesser celandine (Ranunculaceae) is a perennial weed with tuberous root. Tubers are the most important means of reproduction and dispersion of this weed. In recent years, it has spread into wheat fields in Western Iran, mainly in the Lorestan province. A series of experiments were conducted to determine cardinal temperatures and to study the effects of pre-chilling, temperature fluctuations, tuber size, freezing and drying on germination of the tubers, as well as the effect of planting depth on sprouting of the tubers. The results obtained showed that the highest percentage of germination occurred when tubers were stored for more than 2 weeks at 4 or 8 o C. The optimum temperature for germination differed in large and small tubers (8 and 14 o C, respectively). Germination was the highest (almost 100%) at temperature fluctuations of 5-10 o C. Germination of the finger-like and small tubers was the highest (95%); however, very small, small, and broken tubers showed the lowest germination percentage. In the freezing experiment, decreasing the temperature and increasing the storage duration decreased the germination of tubers. Increasing the osmotic potential and temperature resulted in decreased tuber germination of Lesser celandine. Lesser celandine could sprout down to 20 cm depth but heat demand for tubers from superficial depth was smaller than for tubers planted at greater depth.Keywords: freezing; germination; osmotic potential; tuberous root.RESUMO -Celidônia, pertencente à família Ranunculaceae, é uma planta invasora perene com raiz tuberosa. Os tubérculos são o meio de reprodução e dispersão mais importante. Nos últimos anos, essa espécie começou a invadir lavouras de trigo no oeste do Irã, principalmente na província de Lorestan. Experimentos foram conduzidos para determinar as temperaturas limítrofes e estudar os efeitos de pré-resfriamento, flutuações de temperatura, tamanhos de tubérculos, congelamento e dessecação sobre a germinação de tubérculos, bem como da profundidade de plantio sobre a brotação de tubérculos. Os resultados mostraram que a maior porcentagem de germinação ocorreu quando os tubérculos foram armazenados por mais de duas semanas a 4 ou 8 o C. A temperatura ótima para germinação foi diferente em tubérculos grandes e pequenos (8 e 14 o C, respectivamente). A germinação foi maior (quase 100%) sob variações de temperatura entre 5 e 10 o C. A germinação dos tubérculos digitiformes e pequenos foi maior (95%), porém tubérculos muito pequenos, pequenos e danificados apresentaram o menor percentual de germinação. No experimento de congelamento, a redução da temperatura e o aumento no tempo de armazenamento diminuíram a germinação dos tubérculos. O aumento do potencial osmótico e da temperatura resultou em diminuição da germinação de tubérculos de celidônia. Essa espécie pode brotar até a 20 cm de profundidade, mas a demanda de calor de tubérculos plantados superficialmente foi menor do que a dos tubérculos plantados em maior profundidade.Palavras-chave: congelamento, germinação, pote...

Does the Distance from the Formal Path Affect the Richness, Abundance and Diversity of Geophytes in Urban Forests and Parks?

“…The substantial cover-abundance of rhizomatous geophytes in forests can be explained by environmental conditions allowing them high vegetative propagation [54][55][56][57] and seedling recruitment [58,59]. Similarly, Ranunculus ficaria forms dense patches by producing not only underground tuberous roots but also aerial bulblets, which can be dispersed by animals, humans and water [60,61]. Moreover, it is a strong competitor to many spring ephemerals because it appears earlier in the season, uses light efficiently and grows fast [60].…”

“…Moreover, Kermack and Rauschert [80] documented that the abundance and vegetative reproduction of R. ficaria can be influenced by inclination, soil texture, moisture, pH and cation exchange capacity. We assumed that trampling (if it is not too intensive) may favor the expansion of R. ficaria in urban forests and parks since its bulblets easily detach from the maternal plants and can be carried on shoes [61]. However, the effect of trampling intensity in urban forests and parks on geophyte survival and dispersal requires further research.…”

Phenological response patterns and productive ability of Fallopia convolvulus to weather variability in Iran

“…Phenology has emerged as an important focus to accurate predict the consequences of species and community responses to climate change (Otso Ovaskainen et al, 2020;Negi et al 2022), evaluate the variation of air temperature on main agricultural ecosystems (Jones et al, 2005;Recasens et al, 2005) and joined broadly with new technologies such as remote sensing data from satellites (Nieto et al, 2021;Younes et al, 2021), as well as the assessment of future trends and impacts (Bock et al, 2011;Morellato et al, 2016). Therefore, it is essential to know how temperature influences both the reproductive cycle and vegetative development of weeds (Danuso et al, 2012;Loddo et al, 2013;Sohrabi Kertabad et al, 2013;Hatfielg & Prueger, 2015;Gherekhloo et al, 2023).…”