The effects of plant size and light availability on male and female reproductive success and functional gender in a hermaphrodite tree species, Magnolia stellata

Botany ◽  
2011 ◽  
Vol 89 (9) ◽  
pp. 593-604 ◽  
Author(s):  
Suzuki Setsuko ◽  
Nobuhiro Tomaru
Keyword(s):  
Reproductive Success ◽  
Tree Species ◽  
Local Population ◽  
Light Availability ◽  
Plant Size ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Female Reproductive Success ◽  
Chloroplast Microsatellite ◽  
Male And Female

Plant size and light availability may affect male and (or) female reproductive success and their relative contribution (functional gender). To test this hypothesis, we identified parents of 184 seedlings in a local population within a metapopulation of a hermaphroditic, insect-pollinated tree species, Magnolia stellata (Siebold & Zucc.) Maxim., using 14 nuclear and 3 chloroplast microsatellite markers. Parent pairs of all the seedlings were determined, and both seed and pollen parents could be distinguished for 49.5% of the seedlings. We also measured the parents’ plant size (diameter at breast height of the thickest ramet within each genet; DBHt) and the relative photosynthetic photon flux density (rPPFD) they received. The proportion of seedlings that originated from selfing was 20.7%. The number of seedlings parental trees produced as seed parents (S) was positively affected by DBHt and rPPFD. DBHt (but not rPPFD) also positively affected the number of seedlings sired as pollen parents (P). The femaleness of the parental trees (S/(S + P)) was positively affected by DBHt, probably because DBHt had a stronger effect on the trees’ reproductive success as seed parents than on their success as pollen parents. These results suggest that plant size affects not only reproductive success (male and female), but also functional gender.

Relationships between flowering phenology and female reproductive success in the Japanese tree species Magnolia stellata

Botany ◽  
2008 ◽  
Vol 86 (3) ◽  
pp. 248-258 ◽  
Author(s):  
Suzuki Setsuko ◽  
Ichiro Tamaki ◽  
Kiyoshi Ishida ◽  
Nobuhiro Tomaru
Keyword(s):  
Reproductive Success ◽  
Flowering Phenology ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Negative Effects ◽  
Female Reproductive Success ◽  
Large Numbers ◽  
Male Phase

We have examined the earliness, duration, and amplitude of flowering genets in a Magnolia stellata (Sieb. et Zucc.) Maxim. population in relation to their size, environmental factors (temperature and light), and female reproductive success (ovule survival rate) over three consecutive years. Average flowering durations of individual flowers, genets, and the whole population in these 3 years were 10.2, 15.2, and 29.0 d, respectively. A bisexual phase (with both female and male phase flowers) in genets spanned 62.9% of the total flowering period, suggesting that geitonogamy can occur. The earliness, duration, and amplitude of flowering genets were all significantly correlated, indicating that genets flower early and long periods have high flowering amplitudes. The three parameters were also significantly correlated with the size of the genets (represented by the diameter at breast height of its thickest ramet) and relative photosynthetic photon flux density at the top of their crowns. Therefore, genets that are large and located in well-lit sites tend to have many flowers, and blossom both earlier and longer. Later-flowering genets have higher female reproductive success, probably because M. stellata is protogynous. Significantly positive correlation between flowering amplitude and female reproductive success suggests that large numbers of flowers increase the attractiveness of genets for pollinators, and this outweighs the negative effects of geitonogamy.

scholarly journals Male and female reproductive success in natural and anthropogenic populations of Malaxis monophyllos (L.) Sw. (Orchidaceae)

2015 ◽  
Vol 39 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Edyta Jermakowicz ◽  
Beata Ostrowiecka ◽  
Izabela Tałałaj ◽  
Artur Pliszko ◽  
Agata Kostro-Ambroziak
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Natural Populations ◽  
Floral Display ◽  
Natural Habitats ◽  
Female Reproductive Success ◽  
Male And Female ◽  
Demographic Processes ◽  
Preliminary Study ◽  
Effective Pollinators

Abstract In the presented study, male and female reproductive success was analyzed in relation to the population size, floral display and pollinators’ availability in natural and anthropogenic populations of the orchid Malaxis monophyllos (L.) Sw. Our results indicated significant differences between all investigated populations in parameters of floral display, including heights and number of flowers per inflorescence, as well the number of flowering individuals and their spatial structure. Additionally, populations differed both in male (pollinia removal) and female (fruit set) reproductive success, but only the fruit set clearly differentiated anthropogenic and natural populations. Despite the average flower number per plant being significantly higher in two of the anthropogenic populations, it was not related to the fruits set, which was significantly lower there. Moreover, our preliminary study concerning the potential pollinators of M. monophyllos showed a higher contribution of flies in natural habitats than in anthropogenic ones. Thus, we can suspect that the main factors influencing the level of female reproductive success in M. monophyllos populations are abundance of effective pollinators, as well as flower visitors, which may have resulted in a different level of pollen discounting in populations. Therefore, further studies concerning breeding system and pollination as important forces that shape demographic processes in M. monophyllos populations are necessary. Our results also indicate that suitable conservation methods in M. monophyllos should always include the preservation of potential pollinators, especially in these new, secondary habitats.

scholarly journals Spatial and temporal variability of canopy cover and understory light in a Cerrado of Southern Brazil

2010 ◽  
Vol 70 (1) ◽  
pp. 19-24 ◽  
Author(s):  
JP. Lemos-Filho ◽  
CFA. Barros ◽  
GPM. Dantas ◽  
LG. Dias ◽  
RS. Mendes
Keyword(s):  
Rainy Season ◽  
Light Availability ◽  
Canopy Cover ◽  
Dry Season ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Spatial And Temporal Variability ◽  
Wet Season ◽  
Area Index ◽  
Understory Plants

Canopy cover has significant effects on the understory environment, including upon light availability for seedling growth. The aim of the present study was to verify spatial heterogeneity and seasonal changes in the canopy cover of a dense Cerrado area, and their relationship to understory photosynthetic active radiation availability. Leaf area index (LAI) values in the rainy season varied from 0.9 to 4.83, with 40% of the values ranging from 4.0 to 5.0, while in the dry season LAI varied from 0.74 to 3.3, with 53% of the values oscilating from 2.0 to 3.0. Understory light (Qi ) and the Lambert-Beer ratio (Qi/Qo) were taken around noon on sunny days (between 11:00 AM and 1:00 PM). They were also statistically different (p < 0.01) between the dry and wet seasons, with 72% of sampled points in the rainy season presenting photosynthetic photon flux density (PPFD) values lower than 250 μmol.m-2/s around noon, whereas in the dry season, most PPFD values varied from 1500 to 1817 μmol.m-2/s , thus providing high light availability for understory plants. In most of the studied sites, understory plants did not even receive enough light for 50% of their photosynthetic capacity in the wet season. In contrast during the dry season, Qi/Qo values of 0.8 to 1.0 were observed in more than 50% of the points, thereby allowing for photosynthetic light saturation. Thus, light variability around noon was higher during the dry season than in the wet season, its heterogeneity being related to spatial complexity in the canopy cover.

scholarly journals On the convertibility of different microsite light availability indices, relative illuminance and relative photon flux density

2001 ◽  
Vol 15 (6) ◽  
pp. 798-803 ◽  
Author(s):  
H. MURAOKA ◽  
H. HIROTA ◽  
J. MATSUMOTO ◽  
S. NISHIMURA ◽  
Y. TANG ◽  
...  
Keyword(s):  
Flux Density ◽  
Light Availability ◽  
Photon Flux ◽  
Photon Flux Density
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