scholarly journals Performance of Iris variegata genotypes in different light conditions: Flowering phenology and reproductive output

Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 679-694 ◽  
Author(s):  
Uros Zivkovic ◽  
Danijela Miljkovic ◽  
Natasa Barisic-Klisaric ◽  
Aleksej Tarasjev ◽  
Stevan Avramov

We analyzed genetic variability and phenotypic plasticity of flowering pattern and reproductive success in 97 clonal genotypes of Iris variegata originating from contrasting light habitats in Deliblato Sands and expressed under different experimental light conditions. Rhizome segments were taken from each of these clones and transplanted in the experimental garden near the Institute for Biological Research in Belgrade. Significant differences between genotypes were found for two traits (start of flowering, average flowering time). Genotypes originating from open and understory habitats significantly differed for three traits (number of flowers, number of capsules/number of flowers, seed mass/capsule). Significant effect of light treatment were found for three traits (number of capsules/number of flowers, seed mass/capsule, average seed mass). Statistically significant correlations between explored traits were generally similar but also to some extent habitat and treatment specific. Comparing these results with research carried out on congeneric species we noted that there are similar responses for some traits, but also significant differences in some components of flowering and fruiting success.

2008 ◽  
Vol 38 (4) ◽  
pp. 844-850 ◽  
Author(s):  
Gregory Peters ◽  
Anna Sala

Thinning and thinning followed by prescribed fire are common management practices intended to restore historic conditions in low-elevation ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) forests of the northern Rocky Mountains. While these treatments generally ameliorate the physiology and growth of residual trees, treatment-specific effects on reproductive output are not known. We examined reproductive output of second-growth ponderosa pine in western Montana 9 years after the application of four treatments: thinning, thinning followed by spring prescribed fire, thinning followed by fall prescribed fire, and unthinned control stands. Field and greenhouse observations indicated that reproductive traits vary depending on the specific management treatment. Cone production was significantly higher in trees from all actively managed stands relative to control trees. Trees subjected to prescribed fire produced cones with higher numbers of filled seeds than trees in unburned treatments. Seed mass, percentage germination, and seedling biomass were significantly lower for seeds from trees in spring burn treatments relative to all others and were generally higher in trees from fall burn treatments. We show for the first time that thinning and prescribed-burning treatments can influence reproductive output in ponderosa pine.


2015 ◽  
Vol 115 (4) ◽  
pp. 605-615 ◽  
Author(s):  
Patrick von Aderkas ◽  
Caroline Teyssier ◽  
Jean-Paul Charpentier ◽  
Markus Gutmann ◽  
Luc Pâques ◽  
...  

2004 ◽  
Vol 20 (5) ◽  
pp. 563-571 ◽  
Author(s):  
Gaku Kudo ◽  
Shizuo Suzuki

The flowering phenology of five alpine dwarf-tree species was observed in the summit region (3900–3950 m elevation) of Mt. Kinabalu on Borneo Island from March 1998 to November 2001. For each target species, 20–50 individual plants were numbered in two observation plots and the number of inflorescences was monitored at 2–3-mo intervals. The flowering patterns varied among species. Rhododendron buxifolium bloomed extensively every March–May at the main plot but the flowering pattern at the subplot was less predictable. Mass flowering occurred in March 1998 when drought stress was very severe due to an El Niño event. Rhododendron ericoides showed continuous flowering throughout the year and high synchrony between the plots. Extensive flowering of Leptospermum recurvum occurred synchronously within and between plots in the early half of 1999, then flowering activity decreased greatly. Photinia davidiana showed an annual flowering cycle but the timing of the peak flowering differed between the plots. Vaccinium stapfianum showed synchronous flowering between the plots and the flowering peak appeared at longer than 1-y intervals. Plant size was positively correlated with mean flower production in all species, and with the flowering frequency of R. ericoides, R. buxifolium, and V. stapfianum at one of the plots at least. Two fleshy-fruited species, P. davidiana and V. stapfianum, had high selfing ability for fruit production and showed relatively low flowering synchrony among individuals in comparison with the other species. These results indicate that the trigger for initiation of flowering may differ among sympatric species in a tropical-alpine ecosystem at least in normal years.


Botany ◽  
2009 ◽  
Vol 87 (5) ◽  
pp. 475-481 ◽  
Author(s):  
Jacob Weiner ◽  
Lars Rosenmeier ◽  
Emma Soy Massoni ◽  
Josep Nogués Vera ◽  
Eva Hernández Plaza ◽  
...  

Several purported cases of plasticity in plant allocation patterns appear to be the effects of size and allometric growth (“apparent plasticity”). To ask whether there is true plasticity (i.e., a change in the allometric trajectory) in reproductive allocation in Senecio vulgaris  L., we grew S. vulgaris plants at high and low levels of water, nutrients, and competition, and analyzed the relationship between vegetative and seed biomass. Plant size was the major determinant of reproductive output, accounting for 83% of the variation in log (seed mass). There were also significant effects of the treatments that were not due to size, accounting for an additional 9% of the variation. The treatments affected the allometric coefficient (intercept), not the allometric exponent (slope) of the relationship, reflecting a small but significant shift in the efficiency of conversion of total plant biomass into reproductive biomass. In a second experiment, we grew S. vulgaris plants at three nutrient levels and allowed all individuals to complete their life cycles. Again, nutrient level had a small but significant effect on the allometric coefficient. Plasticity in reproductive allocation exists, but is very limited. The primary effects of the environment on the reproductive output of S. vulgaris occur via plant size.


2014 ◽  
Vol 204 (3) ◽  
pp. 496-506 ◽  
Author(s):  
Chunhui Zhang ◽  
Charles G. Willis ◽  
Liana T. Burghardt ◽  
Wei Qi ◽  
Kun Liu ◽  
...  

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