scholarly journals Floral Development and Breeding System of Swainsona formosa (Leguminosae)

HortScience ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 117-119 ◽  
Author(s):  
Manfred Jusaitis
Keyword(s):  
Breeding System ◽  
Growth Pattern ◽  
Pollen Germination ◽  
Floral Development ◽  
Anther Dehiscence ◽  
Bird Pollination ◽  
Self Pollination ◽  
Sigmoidal Growth ◽  
Cross Fertilization

Flowers of Swainsona formosa (G. Don) J. Thompson (syn. Clianthus formosus) developed through seven floral stages from buds to open flowers in 17 days. Floral stages were correlated with the sigmoidal growth pattern of the peduncle. Self-pollination was prevented in the species by the presence of a stigmatic cuticle that precluded pollen germination until ruptured, exposing the receptive surface below. Cuticular rupture occurred in nature during bird-pollination and was emulated manually by lightly rubbing a pollen-covered finger across the stigma. The species was self-compatible, and to ensure cross-fertilization when breeding, emasculation before anther dehiscence was essential.

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

2019 ◽  
Vol 157 (04) ◽  
pp. 283-299 ◽  
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.

scholarly journals Silencing of the Ortholog of DEFECTIVE IN ANTHER DEHISCENCE 1 Gene in the Woody Perennial Jatropha curcas Alters Flower and Fruit Development

2020 ◽  
Vol 21 (23) ◽  
pp. 8923
Author(s):  
Chuan-Jia Xu ◽  
Mei-Li Zhao ◽  
Mao-Sheng Chen ◽  
Zeng-Fu Xu
Keyword(s):  
Jatropha Curcas ◽  
Floral Development ◽  
Initial Step ◽  
Biosynthesis Pathway ◽  
Anther Dehiscence ◽  
Phospholipase A1 ◽  
Woody Perennial ◽  
Flower And Fruit Development ◽  
Male Flowers ◽  
Androecium Development

DEFECTIVE IN ANTHER DEHISCENCE 1 (DAD1), a phospholipase A1, utilizes galactolipids (18:3) to generate α-linolenic acid (ALA) in the initial step of jasmonic acid (JA) biosynthesis in Arabidopsis thaliana. In this study, we isolated the JcDAD1 gene, an ortholog of Arabidopsis DAD1 in Jatropha curcas, and found that it is mainly expressed in the stems, roots, and male flowers of Jatropha. JcDAD1-RNAi transgenic plants with low endogenous jasmonate levels in inflorescences exhibited more and larger flowers, as well as a few abortive female flowers, although anther and pollen development were normal. In addition, fruit number was increased and the seed size, weight, and oil contents were reduced in the transgenic Jatropha plants. These results indicate that JcDAD1 regulates the development of flowers and fruits through the JA biosynthesis pathway, but does not alter androecium development in Jatropha. These findings strengthen our understanding of the roles of JA and DAD1 in the regulation of floral development in woody perennial plants.

The Breeding Systems of Stylidium graminifolium and Stylidium productum (Stylidiaceae)

1990 ◽  
Vol 38 (2) ◽  
pp. 217 ◽  
Author(s):  
AJ Willis ◽  
JE Ash
Keyword(s):  
Breeding System ◽  
Seed Set ◽  
Breeding Systems ◽  
The South ◽  
Pollination Experiments ◽  
Australian Species ◽  
South West ◽  
Self Pollination ◽  
Incompatibility System ◽  
Close Relationship

The breeding systems of Stylidiurn grarninifolium and S. producturn (= S. grarninifoliurn var. caulescens) were studied by observing the phenology of individual flowers and inflorescences, and relating the data to a series of pollination experiments within and between the species. Inter-specific pollinations yielded similar levels of seed-set to crosses within the species indicating a close relationship between the taxa. Self-pollination of either species is uncommon; however, when it occurs, the majority of selfed ovules are aborted post-zygotically, probably by a system of recessive lethals, as there is no indication of an incompatibility system. It is concluded that the breeding systems of S. grarninifoliurn and S. productum, two of the few eastern Australian species, are similar to those of many Stylidiurn species from the south-west, casting doubt upon hypotheses that the breeding system has led to high rates of speciation in the south-west.

Breeding System and Tests for Pollen-Limitation in Two Species of Banksia

1990 ◽  
Vol 38 (1) ◽  
pp. 63 ◽  
Author(s):  
RL Goldingay ◽  
RJ Whelan
Keyword(s):  
Breeding System ◽  
Reproductive Output ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Floral Display ◽  
Cross Pollination ◽  
Self Pollination

Three factors that potentially influence fruit set (breeding system, inadequate cross-pollination and variable floral display) were examined for two species of Banksia. Firstly, self-pollination and autogamy treatments failed to produce any fruit in B. spinulosa and produced very few fruit in B. paludosa. This suggests that cross pollen is required to produce the level of fruit set observed in the field. Secondly, when plants were given abundant cross pollen, fruit set was not altered in B. spinulosa but was in B. paludosa. Although the number of follicles per inflorescence was was not different for open- pollinated (control) and manipulated B. paludosa inflorescences, the latter produced twice the proportion of inflorescences with follicles produced by control plants and twice the total number of follicles per plant. Thirdly, larger floral display in open-pollinated B. spinulosa plants was associated with a greater production of fruit. However, larger floral display was not associated with a greater reproductive output in B. paludosa, and we suggest that recurrent pollen-limitation in this species may be responsible for this result.

scholarly journals Flower visitors of Streptocarpus teitensis: implications for conservation of a critically endangered African violet species in Kenya

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10473
Author(s):  
Mark Otieno ◽  
Neelendra Joshi ◽  
Benjamin Rutschmann
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Safety Net ◽  
Critically Endangered ◽  
Flower Visitors ◽  
Critically Endangered Species ◽  
African Violet ◽  
Cross Pollination ◽  
Self Pollination ◽  
Published Evidence

Background The African violets are endangered plant species restricted mainly to the Eastern Arc Mountains biodiversity hotspots in Kenya and Tanzania. These plants grow well in shaded environments with high humidity. Given their restricted geographical range and published evidence of dependance on insect vectors to facilitate sexual reproduction, understanding their pollination biology is vital for their survival. Methods We conducted an empirical study using flower visitor observations, pan trapping and bagging experiments to establish the role of flower visitors in the fruit set of a locally endemic and critically endangered species of African violet in Taita Hills, Kenya, Streptocarpus teitensis. Results The study found that fruit set is increased by 47.8% in S. teitensis when flowers are visited by insects. However, it is important to note the presence of putative autogamy suggesting S. teitensis could have a mixed breeding system involving self-pollination and cross-pollination since bagged flowers produced 26.9% fruit set. Conclusions Insects appear to be essential flower visitors necessary for increased fruit set in S. teitensis. However, there is evidence of a mixed breeding system involving putative self-pollination and cross-pollination suggesting that S. teitensis is somewhat shielded from the negative effects of pollinator losses. Consequently, S. teitensis appears to be protected to a degree from the risks such as reproduction failure associated with pollinator losses by the presence of a safety net in putative self-pollination.

scholarly journals Breeding system and bird pollination of Camellia pubipetala , a narrowly endemic plant from karst regions of south China

2019 ◽  
Vol 34 (4) ◽  
pp. 141-151
Author(s):  
Sheng‐Feng Chai ◽  
Zong‐You Chen ◽  
Jian‐Min Tang ◽  
Man‐Lian Wang ◽  
Rong Zou ◽  
...  
Keyword(s):  
South China ◽  
Breeding System ◽  
Endemic Plant ◽  
Bird Pollination

Floral Initiation and Development in Relation to the Time of Flowering in Banksia coccinea R.Br and B. menziesii R.Br (Proteaceae)

1990 ◽  
Vol 38 (5) ◽  
pp. 487 ◽  
Author(s):  
AM Fuss ◽  
M Sedgley
Keyword(s):  
Floral Development ◽  
Floral Initiation ◽  
Anther Dehiscence ◽  
Reproductive State ◽  
Vegetative Shoot ◽  
Stage 4 ◽  
Floral Bracts ◽  
Stage 1 ◽  
Characteristic Colour ◽  
Scanning Electron

Floral initiation and development in Banksia coccinea and B. menziesii were investigated using scanning electron microscopy in relation to the time of flowering. Floral initiation in both species occurred in late spring. The sequence of floral development was similar for both species but the timing was different. Ten stages of floral development were identified. Stage 1 was a vegetative meristem. Stage 2 signified the transition to the reproductive state, and was characterised by a broadening of the meristem with the production of involucral bracts. There were increases in both height and diameter of the meristem as common bracts (stage 3), floral bracts (stage 4) and florets (stage 5) were initiated. At stage 6 the developing inflorescences were macroscopically visible. This was followed by appearance (stage 7) and subsequent extension of the florets (stage 8). The styles continued to extend once floret extension had ceased causing the perianth to split and the styles to protrude (stage 9), thus imparting to the inflorescences their characteristic colour. Anther dehiscence occurred prior to anthesis of the floret, and the pollen was deposited on the pollen presenter, a distal modified region of the style. At anthesis (stage 10) styles were released from the perianth limb, presenting pollen to foraging insects and birds. Phyllotaxy was spiral throughout development, with a transition from a single genetic spiral in the vegetative shoot to 13 spirals initiating simultaneously in the developing inflorescence. Floral development was slow, taking from 6 to 8 months in B. menziesii prior to peak anthesis between April and July. In B. coccinea macroscopic inflorescences were not observed until May, with peak anthesis occurring between August and November, 9-12 months after initiation. Inflorescence colour showed wide variation in both species, with red and pink being the dominant colours in B. coccinea and B. menziesii respectively.

Breeding system in an alpine species: Rhododendron ferrugineum L. (Ericaceae) in the French northern Alps

1997 ◽  
Vol 75 (5) ◽  
pp. 736-743 ◽  
Author(s):  
Nathalie Escaravage ◽  
André Pornon ◽  
Bernard Doche ◽  
Irene Till-Bottraud
Keyword(s):  
Breeding System ◽  
Floral Morphology ◽  
Floral Traits ◽  
Anther Dehiscence ◽  
Selfing Rate ◽  
Stigma Receptivity ◽  
Fertility Index ◽  
Rhododendron Ferrugineum ◽  
Self Compatibility ◽  
Alpine Shrub

The breeding system of the alpine shrub Rhododendron ferrugineum was studied at two sites of a population (site L and site H) in the French Alps. The aims were to estimate the degree of selling and (or) outcrossing and to determine if floral traits (including floral morphology, pollen to ovule ratio, stigma receptivity) may be related to the breeding system of the shrub. First, floral traits (corolla length and anther, and style heights) were measured, the number of pollen tetrads and ovules were counted, and the date of stigma receptivity and anther dehiscence were recorded. Second, five pollinations treatments (unmanipulated flowers, natural selfing, hand selfing, natural outcrossing, and hand outcrossing) were performed on 35 randomly chosen individuals in each site, and after each treatment the number of seeds per fruit was recorded. The results demonstrate that Rhododendron ferrugineum is self-compatible (self-compatibility index = 0.95 and 0.97; auto-fertility index = 0.92 and 0.98; selfing rate = 0.24 and 0.11 at sites L and H, respectively). Indices values are not significantly different between the two sites and facultatively xenogamous (pollen to ovule ratio = 669.5 ± 280.5 and 845.2 ± 246.9 at sites L and H, respectively). Key words: breeding system, Rhododendron ferrugineum, floral morphology, phenology, P:O ratio.

Breeding System and Pollination Levels of Banksia ericifolia

1991 ◽  
Vol 39 (4) ◽  
pp. 365 ◽  
Author(s):  
RL Goldingay ◽  
SM Schibeci ◽  
BA Walker
Keyword(s):  
Breeding System ◽  
Pollen Tubes ◽  
Fruit Production ◽  
The Self ◽  
Open Pollination ◽  
Flower Number ◽  
Cross Pollination ◽  
Self Pollination ◽  
Full Complement ◽  
Banksia Ericifolia

Experiments were carefully designed to determine the breeding system of Banksia ericifolia L.f. An equivalent percentage of flowers (78%) contained pollen tubes following self-pollination and open-pollination while a significantly smaller percentage of flowers in an autogamy treatment (44%) and cross-pollination treatment (55%) contained pollen tubes. Significantly more of the inflorescences in the open-pollination (60%) and cross-pollination (33%) treatments produced fruit compared with those in the self-pollination (11%) and autogamy treatments (13%). We suggest that B. ericifolia is largely self-incompatible because fruit production did not reflect pollen tube abundances. The influence of pollination levels on fruit production was determined by reducing the number of flowers on an inflorescence to 100 (i.e. 10% of original) or fewer and hand-pollinating these with cross pollen. There was no difference in fruit production between inflorescences with reduced flower number and open-pollinated inflorescences which had their full complement of flowers. Thus, the ability of an inflorescence to produce fruit appears more likely to be determined by the type of pollen received (cross versus self) rather than by the number of pollinated flowers it contains.

DEVELOPMENT OF THE EMBRYO SAC AND EMBRYO OF TEFF, ERAGROSTIS TEF

1966 ◽  
Vol 44 (8) ◽  
pp. 1071-1075 ◽  
Author(s):  
Melak H. Mengesha ◽  
A. T. Guard
Keyword(s):  
Female Gametophyte ◽  
Leaf Blade ◽  
Floral Development ◽  
Flag Leaf ◽  
Embryo Sac ◽  
Eragrostis Tef ◽  
Careful Study ◽  
Embryo Formation ◽  
Self Pollination ◽  
Before And After

A careful study of the floral development of Eragrostis tef indicates that the flowers do not open and that self-pollination is the rule. Observations of the development of the female gametophyte show that it is of the normal monosporic type common to most angiosperms. The three antipodals divide several times as is common in grasses. Study of many ovules before and after fertilization showed absence of any apomictic type of embryo formation. Fertilization was found to occur in the basal floret of a spikelet when that floret was at the base of the flag leaf blade.

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