Reproductive Biology and Floral Phenologies of the Sympatric Species Leptospermum myrsinoides and L. continentale (Myrtaceae)

The reproductive biology and floral phenologies of co-occurring Leptospermum myrsinoides and L. continentale were investigated. Both species have similar floral structure and both are protandrous. Anther dehiscence is staggered over approximately 6 days and pollen viability remains high for at least 3 days. The styles of both species are short at anthesis but extend during the next 6 days to approximately the same height as the anthers. The stigmas of these species do not achieve maximum receptivity until at least 4 days after anthesis. Both species are self-compatible. At the three sites studied, L. myrsinoides and L. continentale have separate flowering times with L. myrsinoides always flowering first. Within populations of each species, plants reached first flower and peak flower in the same order in 1989 and 1990, implying genetic control over flowering time. It is suggested that protandry in these species enhances the likelihood of outcrossing and the staggered release of pollen coupled with the degree of overlap within flowering populations increases the number of potential mates available to each flower.

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Reproductive biology of four weedy Euphorbia species from Ile-Ife, Nigeria

Ife Journal of Science ◽

10.4314/ijs.v22i1.1 ◽

2020 ◽

Vol 22 (1) ◽

pp. 1-8

Author(s):

A.O. Bolaji ◽

M. Idowu-Aiye ◽

H.O. Moronfade

Keyword(s):

Seed Dispersal ◽

Reproductive Biology ◽

Pollen Viability ◽

Seedling Emergence ◽

Floral Structure ◽

Euphorbia Prostrata ◽

Spread Parameters ◽

Reproductive Phases ◽

Vegetative Phases ◽

Explosive Mechanism

Euphorbia heterophylla Linn., Euphorbia hirta Linn., Euphorbia hyssopifolia Linn. and Euphorbia prostrata Linn. are four noxious, yet economically important weeds, useful as phytomedicine in some parts of the world and also in Nigeria. Studies were carried out on their reproductive biology with a view to understanding the mode of their spread. Parameters investigated include number of days to seedling emergence, germinationpercentage, number of days to flowering, period to anthesis, pollinators, pollen viability, pollen size, floral structure, fruits type, seeds type, average number of fruit per plant, average number of seeds per plant and mode of seed dispersal. Results obtained showed that the seedlings of the four Euphorbia species studied emerged within 3 to 5 days; numbers of days to 50% flowering took 44 to 58 days; while flowering and fruiting continuedthroughout the remaining part of the year; thus exhibited r-strategy, expending more time and allocation of resources on their reproductive phases than their vegetative phases. Also differences existed in their stigma shape, perianth colour, perianth texture, pollen sizes, pollen viability as well as ripened colour of seed which were all significant characters that could be useful in delimiting the species. Furthermore, the study revealed that thefour species were essentially insect pollinated and their seeds dispersed by means of explosive mechanism usually characteristic of their schizocarpic fruits. This ability as well as their tendency to exhibit r-strategy could probably account for their ability to spread and invade cultivated fields, waste lands and roadsides. Keywords: Explosive mechanism, r-Strategy, Seed dispersal, Pollen viability, Seed set

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Reproductive-Biology of the Australian Species of the Genus Pandorea (Bignoniaceae)

Australian Journal of Botany ◽

10.1071/bt9930611 ◽

1993 ◽

Vol 41 (5) ◽

pp. 611 ◽

Cited By ~ 14

Author(s):

EA James ◽

RB Knox

Keyword(s):

Reproductive Biology ◽

Pollen Viability ◽

Pollen Tubes ◽

Breeding Program ◽

Breeding Systems ◽

Fluorescein Diacetate ◽

Anther Dehiscence ◽

Stigma Receptivity ◽

Australian Species ◽

Incompatibility Barrier

We studied the reproductive biology of Australian species of Pandorea to facilitate a breeding program designed to develop elite cultivars for the horticultural industry. P. pandorana is protogynous whereas anther dehiscence and stigma receptivity occur at the same time in P. jasminoides and P. baileyana. The stigmas of all species are receptive prior to anthesis and can be artificially pollinated at this stage provided that the stigma lobes can be separated. Pollen viability, tested for P. pandorana and P. jasminoides, deteriorated during the flower life although pollen samples with a low Fluorescein diacetate response (5-14%) still produced many pollen tubes which grew to the base of the style. For all species tested, pollen tubes grew into the ovary in both outcross pollinations and in self pollinations which are known to be incompatible indicating that the incompatibility barrier is within the ovary. Pollen-ovule ratios, determined for P. pandorana and P. jasminoides, were low compared with other published pollen-ovules ratios for taxa with breeding systems based on outcrossing.

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Spikelet fertility and heat shock transcription factor (Hsf) gene responses to heat stress in tolerant and susceptible rice (Oryza sativa L.) genotypes

The Journal of Agricultural Science ◽

10.1017/s002185961900056x ◽

2019 ◽

Vol 157 (04) ◽

pp. 283-299 ◽

Cited By ~ 3

Author(s):

C. Malumpong ◽

S. Cheabu ◽

C. Mongkolsiriwatana ◽

W. Detpittayanan ◽

A. Vanavichit

Keyword(s):

Heat Stress ◽

Pollen Germination ◽

Seed Set ◽

Oryza Sativa L ◽

Flag Leaf ◽

Pollen Viability ◽

Spikelet Fertility ◽

Anther Dehiscence ◽

Spikelet Sterility ◽

Plant Parts

AbstractThe reproductive stage of rice is the most sensitive to heat stress, which can lead to spikelet sterility. Thus, heat-tolerant and heat-susceptible genotypes were used to investigate their differences in terms of phenotypic responses and expression changes of Hsf genes at the pre-flowering stage under heat stress. Results clearly showed that panicles had the highest temperature compared with other plant parts under both natural and heated conditions. However, the temperatures of tolerant and susceptible genotypes were not significantly different. In terms of spikelet fertility, the tolerant lines M9962 and M7988 had high seed set because their anther dehiscence, pollen viability and pollen germination were only slightly affected. In contrast, the susceptible line Sinlek showed severe effects at all steps of fertilization, and the pollen viability of M7766 was slightly affected under heat stress but was more affected in terms of anther dehiscence and pollen germination. Both susceptible lines showed dramatically decreased seed set. In addition, the expression of six HsfA genes in the flag leaves and spikelets at the R2 stage of plants under heat stress showed different responses. Notably, expression of the HsfA2a gene was predominantly upregulated in the flag leaf and spikelets under heat stress in M9962. Therefore, it can be concluded that heat stress has severe effects on the stamen, and that different genotypes have different susceptibilities to heat stress.

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Reproductive biology of Melaleuca alternifolia (Myrtaceae) 1. Floral biology

Australian Journal of Botany ◽

10.1071/bt10035 ◽

2010 ◽

Vol 58 (5) ◽

pp. 373 ◽

Cited By ~ 3

Author(s):

L. Baskorowati ◽

M. W. Moncur ◽

J. C. Doran ◽

P. J. Kanowski

Keyword(s):

Reproductive Biology ◽

Floral Biology ◽

Morphological Development ◽

Tea Tree Oil ◽

Melaleuca Alternifolia ◽

Tea Tree ◽

Viable Seeds ◽

Individual Trees ◽

Days After Anthesis ◽

Flowering Intensity

Melaleuca alternifolia (Maiden & Betche) Cheel is commercially important as the source of essential oil for the Australian tea tree-oil industry. Information on reproductive biology of M. alternifolia is important to the Australian breeding program directed at improving the quality and quantity of tea tree oil. Flowering in three geographically separated sites – two planted seed orchards and one managed natural population, all in NSW – was observed in the present study, with supporting data obtained from glasshouse-grown plants in Canberra. The majority of the work was conducted from 2004 to 2007, although the study also drew on some prior observations. M. alternifolia has spikes of flowers that open acropetally over a 6-day period. No strong separation of male and female phases was found in any individual flower; pollen was shed by 1.4 days after anthesis and the stigma reached peak receptivity 3–5 days after anthesis. Dichogamy and acropetal floral development may lead to geitonogamy. Flowering occurred during the months of October–November, with the peak in November, and was synchronous across all three sites. Flowering intensity and success in producing capsules appeared to be associated with total spring rainfall. Initiation of flowering in M. alternifolia appears to be correlated with daylength, or an environmental parameter closely correlated with daylength. Flowering intensity varied considerably among the years surveyed, sites and families, and appears to be promoted by a period of winter minimum temperatures below 5°C. In M. alternifolia, the morphological development of buds, flowers and fruit leading to the development of mature seed takes place over a period 16–18 months from flowering. M. alternifolia differed significantly in the number of viable seeds per capsule from individual trees, from 26 ± 3.8 to 57 ± 3.8 germinants.

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Phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca, Vitaceae) cultivated in northeastern Brazil

Brazilian Journal of Biology ◽

10.1590/1519-6984.05315 ◽

2016 ◽

Vol 76 (4) ◽

pp. 975-982 ◽

Cited By ~ 7

Author(s):

N. A. S. Nunes ◽

A. V. Leite ◽

C. C. Castro

Keyword(s):

Reproductive Biology ◽

Pollen Viability ◽

Floral Biology ◽

Climatic Conditions ◽

Northeastern Brazil ◽

Growing Degree Days ◽

Base Temperature ◽

Vitis Labrusca ◽

Degree Days ◽

Inflorescence Development

Abstract Phenology and reproductive biology of cultivated species are important for the comprehension of the requirements for fruit and seed production and the management of pollinators. This study aimed to characterise the phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca) in northeastern Brazil during January 2011 (P1), Augst 2011 (P2), April 2012 (P3) and August 2012 (P4). We recorded the duration (days) of the phenological stages, pruning (P), woolly bud (W), budburst (B), inflorescence development (ID), flowering (F), ripening (R) and harvest (H). We analysed the floral biology, the sexual system and the breeding system. We measured the growing degree days (GDD) required to reach the subperiods P-B, B-F and F-H. The periods P1, P2, P3 and P4 lasted for 116, 125, 117 and 130 days, respectively. The number of days of harvest were similar in the same dry (P1 and P3) and rainy (P2 and P4) periods. All the periods that we recorded were shorter than those observed in other regions of Brazil, which may be attributable to the mean temperature and carbohydrate metabolism. The flowers are green, hermaphroditic, with an odour of mignonette, low pollen viability and autogamous. The base temperature of 10°C was considered the most adequate for the subperiods as has been documented for other grape varieties in Brazil. Thus, temperature was also the most adequate for the cycles, presenting a smaller standard deviation (0.119, 0.147, 0.156 and 0.153 to P1, P2, P3 and P4, respectively) when compared to a base temperature of 12°C (0.122, 0.158, 0.165 and 0.160 to P1, P2, P3 and P4, respectively). The higher and the lower observed GDD were 1972.17 and 1870.05, respectively, both above the values recorded in other parts of Brazil for same variety. The phonological results, including knowledge of growing degree days, are important to the planning of cultures at the study site and in other regions that have similar climatic conditions and make it possible to pre-determine the harvest.

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Onset and duration of stigma receptivity in Kunzea pomifera (Myrtaceae)

Australian Journal of Botany ◽

10.1071/bt05122 ◽

2006 ◽

Vol 54 (6) ◽

pp. 559 ◽

Cited By ~ 5

Author(s):

T. Page ◽

G. M. Moore ◽

J. Will ◽

G. M. Halloran

Keyword(s):

Pollen Tube ◽

Reproductive Biology ◽

Peroxidase Activity ◽

Pollen Tube Growth ◽

Seed Set ◽

Stigma Receptivity ◽

Controlled Pollination ◽

Germinated Pollen ◽

New Crop ◽

Days After Anthesis

The onset and duration of stigma receptivity in K. pomifera was evaluated by observing stigma peroxidase activity, pollen-tube growth and seed set, following controlled pollination of flowers of different ages. Peroxidase activity was negligible from 1 day before to 4 days after anthesis, increasing to a peak of 65% at Day 13. The percentage of pistils bearing germinated pollen and ovaries exhibiting pollen-tube entry increased when pollen was applied to the stigma from the day before anthesis, to a maximum at Days 6 and 7 after anthesis, respectively, followed by a decline by Day 9. Under greenhouse conditions the optimum pollination period, measured as the level of set seed after pollination, ranged from 2 to 11 days after anthesis. The knowledge of this aspect of the species reproductive biology is of considerable value in controlled pollinations for its improvement as a new crop.

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Reproductive biology of two sympatric colubrid snakes, Chironius flavolineatus and Chironius quadricarinatus, from the Brazilian Cerrado domain

Amphibia-Reptilia ◽

10.1163/017353710x518423 ◽

2010 ◽

Vol 31 (4) ◽

pp. 463-473 ◽

Cited By ~ 6

Author(s):

Roberta Richard Pinto ◽

Otavio Augusto Vuolo Marques ◽

Ronaldo Fernandes

Keyword(s):

Reproductive Biology ◽

Sexual Maturity ◽

Egg Production ◽

Sympatric Species ◽

Egg Laying ◽

Reproductive Pattern ◽

Brazilian Cerrado ◽

Wet Season ◽

Reproductive Cycles ◽

First Time

AbstractThe reproductive biology of Chironius flavolineatus and C. quadricarinatus from the Brazilian Cerrado domain is described, including sexual maturity, female fecundity, and reproductive cycles of males and females. Egg-laying is recorded here for the first time for C. quadricarinatus. Males of both species attain sexual maturity with a smaller snout-vent length than females. Females of C. flavolineatus have an extended reproductive cycle with egg production during the wet season, whereas males exhibit year-round sperm production. Chironius quadricarinatus has continuous reproductive cycles in both sexes. Differences in reproductive pattern between these two sympatric species are probably related to phylogenetic constraints on intrageneric lineages of Chironius.

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Observations on Natural Pollination in Commercial Plantings of Oil Palm (Elaeis Guineensis) in Malaya

Experimental Agriculture ◽

10.1017/s0014479700021864 ◽

1967 ◽

Vol 3 (2) ◽

pp. 105-116 ◽

Cited By ~ 10

Author(s):

J. J. Hardon ◽

P. D. Turner

Keyword(s):

Oil Palm ◽

Elaeis Guineensis ◽

Pollen Viability ◽

Pollen Dispersal ◽

Early Morning ◽

Total Rainfall ◽

Atmospheric Pollen ◽

Natural Pollination ◽

Pollen Density ◽

Days After Anthesis

SummaryMost oil palm pollen is produced by male inflorescences 2–3 days after anthesis, and this pollen is the most viable. When protected, pollen viability on female inflorescences is good up to 6 days, after which it declines. The majority of the pollen remains below the canopy, especially at bunch level. Results of quantitative evaluation of pollen dispersal showed that atmospheric pollen density is very variable and is governed by numerous factors. There is a marked diurnal variation, with highest pollen density during the afternoon and a negligible amount during the night and early morning. Rain causes an immediate drop in concentration, but pollen densities were influenced more by the number of days on which rain was recorded than by total rainfall. A relationship exists between pollen density, the number of male inflorescences in the vicinity, and rainfall, but the effects of relative humidity, sunshine and wind are obscure. Whilst pollen density drops rapidly within a short distance from the inflorescence, there is a significant dispersal over greater distances than previously thought.

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