The Reproductive Biology of Agavaceae: I. Pollen and Nectar Production in Four Arizona Agaves

1977 ◽  
Vol 22 (2) ◽  
pp. 157 ◽  
Author(s):  
William M. Schaffer ◽  
M. Valentine Schaffer

Plant Biology ◽  
2015 ◽  
Vol 18 (1) ◽  
pp. 73-83 ◽  
Author(s):  
M. J. Pérez-Crespo ◽  
J. F. Ornelas ◽  
S. Martén-Rodríguez ◽  
A. González-Rodríguez ◽  
C. Lara


1996 ◽  
Vol 74 (12) ◽  
pp. 1996-2001 ◽  
Author(s):  
Guillermo L. Rivera ◽  
Leonardo Galetto ◽  
L. Bernardello

Some aspects of the reproductive biology of Ligaria cuneifolia have been studied, addressing the following questions: (i) Are there temporal differences in the female and male functions? (ii) How do nectar composition, volume, concentration, and amount of sugar vary throughout the flower lifetime? (iii) How does the plant respond to nectar removal? (iv) What is the breeding system of this species? Flowers last 4 days. There is a predominance of the male function in the first days and of the female function in the last days. Chemical composition of nectar varies throughout the flower lifetime; there is a constant decrease in sucrose along with an increase in glucose. Nectar is secreted during nights, and every secretion period is followed by a cessation interval. After the final cessation, a period of active resorption follows. During the mostly male phase of the flower, nectar has more sucrose than hexose, its secretion is discontinuous, and nectar removal reduces the rate of nectar production. During the mostly female phase, nectar has more hexose than sucrose, its secretion ceases, nectar removal does not affect nectar production, and a resorption period is inferred. Tests for spontaneous autogamy and apomixis were negative. Low fruit set is obtained when autogamous, geitonogamous, and xenogamous hand pollinations are performed on flowers less than 2 days old compared with flowers at least 3 days old (0, 15, and 47% versus 19, 37.5, and 89%, respectively). These results indicate the the reproductive system of L. cuneifolia is primarily xenogamous, but reproductive success is related to flower age. Keywords: Loranthaceae, Ligaria, nectar chemistry, breeding system, flower phenology, reproductive biology.



2021 ◽  
Vol 43 (2) ◽  
Author(s):  
Mariluz Aguilar Castro ◽  
Daily Gómez Ramírez ◽  
Verónica Álvarez Osorio ◽  
Sandra Muriel Ruiz

Abstract In Colombia there is a large diversity of promising fruit trees, one of them is Matisia cordata. Sapoti species is appreciated by the consumers, although it is produced in small volumes by traditional productors. The objective of this research is to describe the floral and reproductive biology of sapoti, including floral visitors that act as biotic pollination agents. The study was conducted in two farms, between February/2016 and July/2017. In the first farm, floral buds were marked to follow the stages until fruit formation, pollination mechanism was studied, and floral visitors were collected for identification. In the second farm, flowers were marked to measure the floral nectar production. The duration from floral bud to ripe fruit was 269 days, the 2.7% of the flowers reached the fruit stage. Twenty-five floral visitors were registered, seven of which contacted the sexual whorls, specially Meliponini bees, hummingbirds and bats from Artibeus and Glossophaga genus. M. cordata is a prevalently allogamous species, it attracts diurnal and nocturnal animals, which can contribute to the pollination process. The flowers produced 1.6 ml of nectar with a sugar content from 6.2 to 11 °Brix. The sapoti flowers constitute an abundant and valuable resource for animals from the region.



Rodriguésia ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 919-926 ◽  
Author(s):  
Jacilene Bezerra da Silva ◽  
Ana Virgínia de Lima Leite

Abstract Reproductive biology and pollination of the fanwort, Cabomba aquatica Aubl., were studied in populations from dams located in Dois Irmãos State Park, Recife, Pernambuco state, northeastern Brazil. Flower anthesis in this species is diurnal and lasts two days. The flowers are bisexual and exhibit herkogamy and incomplete protogyny. Each flower produces an average of 2.1 ± 94.8 pollen grains, with a P/O ratio of 1.055 and high pollen viability (99.7%). This species is self-compatible, but requires biotic vectors to transfer pollen. We observed visits of bees (Apidae and Halictidae), wasps (Vespidae) and flies (Diptera) to the flowers. Bees and wasps were considered to be effective pollinators, both due to their behavior and their high frequency of visits to flowers, whereas flies were considered to be occasional pollinators. The floral mechanism (herkogamy and protogyny), together with low nectar production and pollinator behavior during visits, may contribute to increase pollen flow between individuals.



Author(s):  
Alan N. Hodgson

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.



1989 ◽  
Vol 100 (3-4) ◽  
pp. 137-145
Author(s):  
R. E. Ugborogho ◽  
C. O. Agomo
Keyword(s):  


1986 ◽  
Vol 14 (1) ◽  
pp. 1-41 ◽  
Author(s):  
Thomas Laqueur
Keyword(s):  


2009 ◽  
Vol 40 ◽  
pp. 59-73 ◽  
Author(s):  
E A Filina ◽  
V N Khlivnoy ◽  
V I Vinnichenko
Keyword(s):  


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