scholarly journals Reproductive assurance in three Neotropical species of Podostemaceae: strategies of self-pollination and the first report of apomixis1

Hoehnea ◽  
2020 ◽  
Vol 47 ◽  
Author(s):  
Inara Carolina da Silva-Batista ◽  
Cristiana Koschnitzke ◽  
Claudia Petean Bove

ABSTRACT (Reproductive assurance in three Neotropical species of Podostemaceae: strategies of self-pollination and the first report of apomixis). The aspects of reproductive assurance of the Lophogyne lacunosa (Gardner) C.P.Bove & C.T.Philbrick, Podostemum weddellianum (Tul.) C.T. Philbrick & Novelo, and Tristicha trifaria (Bory ex Willd.) Spreng. were investigated and, the mechanisms correlated to the flower morphology and floral biology. The mating system of L. lacunosa was also described, as well as the first report of apomixis in Podostemaceae. The reproductive assurance strategies used by L. lacunosa were autonomous competitive self-pollination, wind pollination, and apomixis. This species has floral attributes that ensure the dispersion of pollen by wind and its capture by the stigmas. Podostemum weddellianum and Tristicha trifaria presented autonomous competitive self-pollination before and during anthesis, respectively; both lack floral attributes for wind pollination. Considering that these species can be found in the same running water environment and that they are not phylogenetically close related, it was concluded that the different reproductive strategies are related to their evolutionary lineages.

2020 ◽  
Author(s):  
Maureen Murua ◽  
Anahí Espíndola ◽  
Fernanda Pérez

Abstract Bachground: One of the most common evolutionary transitions in angiosperms is the reproductive change from outcrossing to self-fertilization, which has occurred independently in many lineages. This transition has been associated with changes in floral biology, ecology and genetics, with selfing species experiencing reduced floral display and herkogamy, rapid plant growth, and increased inbreeding depression. Here, we aim to test whether self-compatibility was associated with a reduction in floral traits important to the attraction and interaction with pollinators, and a reduction in genetic diversity and inbreeding. Results: Our self-incompatibility tests indicated that 50% of the species studied here are self-incompatible. In relation to floral traits, we found that self-incompatible species do not show a reduction in the size of their floral traits, but rather we found larger corolla, elaiophore area, and herkogamy in self-compatible ones. The microsatellite analysis did not identify any significant decrease in the genetic diversity or increase in inbreeding levels in the self-compatible Calceolaria species. Conclusions: Despite our results go against our expectations, in the case of Calceolaria , their high dependence on only two genera of oil-bees put the species in a vulnerable position, probably facilitating the evolution of mechanisms of reproductive assurance in the absence of pollinators. As a result, the plants maintain their attraction traits while evolving an ability to self. In addition, we also did not detect a significant change in genetic diversity or inbreeding when different reproductive strategies are used. This suggests that selfing could be delayed, facilitating -when possible- the exchange of genes by cross-pollination first, and buffering the negative genetic effects of self-pollination.


2011 ◽  
Vol 59 (1) ◽  
pp. 61 ◽  
Author(s):  
Yash Mangla ◽  
Rajesh Tandon

Low fruit-set in obligately outbreeding plant species is attributed to a variety of reasons that can be ascertained from reproductive studies. In the present work, the causes of poor natural fruit-set in Crateva adansonii DC. were investigated. Floral biology, the role of wind and insects in pollination and the breeding system of the species were studied in two natural populations for three consecutive seasons (2006–08). The flowers exhibited traits conducive to a mixture of wind and insect pollination (ambophily). Although a variety of insects visited the flowers, they were ineffective in pollinating. Nevertheless, active foraging by the honeybees (Apis dorsata, A. mellifera and A. cerana indica) facilitated enhanced pollen dispersal in the air and resulted in indirect pollination by wind. Airborne pollen grains pollinated the plants only up to 10 m. Fruit-set from open pollination was comparable to wind-pollinated flowers. Supplemental pollination treatments established the occurrence of strong self-incompatibility (SI) (index of SI = 0.14). Spontaneous autogamy was prevented by pronounced herkogamy. Low natural fecundity in C. adansonii is due to pollination failure, pollen limitation (pollen limitation index = 0.98) and the sparse distribution of the conspecifics; partial SI may partly ensure reproductive assurance through geitonogamy. In the absence of a pollinator wind appears to act as a secondary mode of pollination.


2021 ◽  
Vol 25 (03) ◽  
pp. 710-721
Author(s):  
Écio Souza Diniz ◽  
◽  
Rodolfo Oliveira Costa ◽  
Larissa Areal Carvalho Müller ◽  
Jan Thiele ◽  
...  

Chrestas capigera (Less.) Gardner is an important medicinal herb which, however, has been poorly studied for its biology and ecology. This study aimed to investigate its phenology, floral biology, reproductive biology (self-pollination tests), spatial distribution and correlations between phenophases and climatic data in two sites (Cerrado stricto sensu and Campo rupestre) in southern Minas Gerais, Brazil. From August of 2012 to August of 2013, we monitored phenophase occurrence for 70 individuals: emission of new leaves, flowering, production of immature fruits, and mature fruits. Floral anthesis occurred during daytime and remained all day until fruit formation. Peak leaf emergence was observed in April, correlating with minimum monthly temperature and mean monthly precipitation. Flowering and green fruit peaked in May and June, respectively, and correlated negatively with all climatic variables. Mature fruits peaked in June, but did not correlate significantly with any of the climatic variables. However, no difference was found between the two sites regarding the timing of phenophases. The spatial distribution pattern of individuals within sites was random. The self-pollination tests showed that the individuals pollinated and fertilized themselves. Our findings allow us to conclude that the phenology of C. scapigera has pronounced phenological seasonality with reproductive peak activities in the drier and colder season, which is congruent with the self-pollination and anemochoric dispersion strategy.


2019 ◽  
Vol 192 (4) ◽  
pp. 840-854
Author(s):  
Aline C Gomes ◽  
Bruno H S Ferreira ◽  
Camila S Souza ◽  
Luan M M Arakaki ◽  
Camila Aoki ◽  
...  

Abstract Some epiphytes are adapted to extreme environments with the ability to survive drought as a result of their morphological (xeromorphism), anatomical (foliar trichomes or scales) and physiological features. In contrast to vegetative features, they may have diverse sexual reproductive strategies. Here we compared the flowering morphology, floral biology, breeding system and pollinators of Tillandsia duratii, T. loliacea and T. recurvifolia (Bromeliaceae) adapted to an extreme environment, the Brazilian Chaco. Tillandsia duratii and T. recurvifolia flower for 5–6 months, whereas T. loliaceae flowers for 11 months, mainly in the dry season, with low to high flowering overlap between them. Although these species generally show similar flowering morphology, they differ in size, colour, odour and/or floral functionality, suggesting non-sharing of pollinators among them. Bimodal pollination occurs in T. duratii (bees, moths other than hawkmoths) and T. recurvifolia (butterflies, hummingbirds); in T. loliacea, we recorded no floral visitors. Tillandsia recurvifolia is self-incompatible, has flowers which approach herkogamy and protandry, and depends on pollen vectors for fruit set. The other two species show reverse herkogamy, autonomous self-pollination and self-compatibility (mixed breeding system); therefore, pollinators are not required. The disparity in reproductive strategies among the three species suggests the possibility of selection for diverse modes of reproduction.


2012 ◽  
Vol 26 (1) ◽  
pp. 243-250 ◽  
Author(s):  
Juliana Ordones Rego ◽  
Edivani Villaron Franceschinelli ◽  
Daniela Cristina Zappi

Cipocereus laniflorus N.P. Taylor & Zappi is an endemic species from the Serra do Caraça, State of Minas Gerais, Brazil. In order to propose conservation strategies for this species, its reproductive strategies were investigated, including reproductive phenology, floral biology, floral visitors and breeding system. The flowering and fruiting period extends from May to October. Few flowers per plant open each night, producing up to 0.4 ml nectar, but 30% of them are nectarless. Probably pollen is also offered as a resource. Fruiting efficiency of C. laniflorus (47%) is close to that found in other Cactaceae species. Pollen of this species was detected in Anoura geoffroy, Soricina glossophaga and Pygoderma bilabiatum bats. Amongst the characteristics related to bat-pollination syndrome found in C. laniflorus, the cream-white colouring of the internal part of the flower, the numerous stamens and the nocturnal anthesis of short duration can be highlighted. Flowers of C. laniflorus are also visited by Nitidulidae beetles, Trigona fulviventris bees and hummingbirds, however bats are the main pollinators of this species. Finally, as a self-sterile species, C. laniflorus needs a pollinator and is more susceptible to the risk of extinction if local disturbances affect its pollination system.


Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1377
Author(s):  
Maureen Murúa ◽  
Anahí Espíndola ◽  
Fernanda Pérez

One of the most common evolutionary transitions in angiosperms is the reproductive change from outcrossing to selfing, commonly associated with changes in floral biology and genetic diversity. Here, we aim to test whether self-compatibility leads to a reduction of floral traits and genetic diversity. For this, we experimentally estimate levels of self-compatibility, measure three floral traits and estimate four genetic diversity parameters using nine microsatellites in nine Calceolaria species. Our analysis indicated that four of the study species were self-incompatible. In addition, we found that self-compatible species did not show a reduction in floral traits size, but rather displayed larger corolla and elaiophore areas. Our analyses of genetic diversity identified larger allele number and observed heterozygosity in selfers than in outcrossers, but did not find larger inbreeding in the self-compatible species. Even though our results contradict our expectations, in the case of Calceolaria, their high dependence on only two genera of oil-bees puts the genus in a vulnerable reproductive position, probably facilitating the evolution of reproductive assurance mechanisms in the absence of pollinators. As a result, plants maintain their pollinator attraction traits while evolving the ability to self, possibly in a delayed way.


2012 ◽  
Vol 60 (2) ◽  
pp. 154 ◽  
Author(s):  
X. Zhou ◽  
H. Lin ◽  
X.-L. Fan ◽  
J.-Y. Gao

Reproductive biology of saprophytic plants has been poorly studied. Epipogium roseum (D.Don) Lindl. is a small saprophytic orchid that is widely distributed in tropical and subtropical Asia, Australia and Africa. The floral biology and insect visitation of E. roseum were studied in Xishuangbanna, south Yunnan Province, China. E. roseum possesses an obligate self-pollination system, in which the degenerative rostellum has lost its function as a physical barrier separating the stigma and stamens (pollinia), allowing contact between the stigmatic secretions and the pollinia during bud development. Flowers of E. roseum usually open and successfully attract insect visitors. The Asian honey bee (Apis cerana cerana) was the only visitor observed, and regularly visited flowers of E. roseum for nectar. However, these bees did not carry pollinia away after visiting the flowers due to the absence of a viscid disk in E. roseum; the results of experiments also indicated that the Asian honey bee does not contribute to fruit set in E. roseum. The visiting frequency of Asian honey bees to flowers of E. roseum varied both spatially and temporally. E. roseum does not undergo outcrossing mediated by insects and is adapted to obligate self-pollination. We suggest that this may have evolved because of the uncertainty of pollinator services associated with its saprophytic lifestyle. Our current studies do not support the hypothesis that obligate autogamy is favoured by myco-heterotrophic plants due to resource limitations.


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