scholarly journals Temperature-driven flower longevity in a high-alpine species ofOxalisinfluences reproductive assurance

2013 ◽  
Vol 200 (4) ◽  
pp. 1260-1268 ◽  
Author(s):  
Mary T. K. Arroyo ◽  
Leah S. Dudley ◽  
Gus Jespersen ◽  
Diego A. Pacheco ◽  
Lohengrin A. Cavieres
Keyword(s):  
Flower Longevity ◽  
Reproductive Assurance ◽  
Alpine Species

scholarly journals Flowering Phenology Adjustment and Flower Longevity in a South American Alpine Species

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 461
Author(s):  
Mary T. K. Arroyo ◽  
Ítalo Tamburrino ◽  
Patricio Pliscoff ◽  
Valeria Robles ◽  
Maria Colldecarrera ◽  
...  
Keyword(s):  
Natural Populations ◽  
Flowering Phenology ◽  
Snow Accumulation ◽  
Growth Potential ◽  
Controlled Study ◽  
Temperature Threshold ◽  
Flower Longevity ◽  
Passive Warming ◽  
Alpine Species ◽  
Flowering Onset

Delayed flowering due to later snowmelt and colder temperatures at higher elevations in the alpine are expected to lead to flowering phenological adjustment to prevent decoupling of peak flowering from the warmest time of the year, thereby favoring pollination. However, even if flowering is brought forward in the season at higher elevations, an elevational temperature gap is likely to remain between the high- and low-elevation populations of a species at the time these reach peak flowering on account of the atmospheric reduction in temperature with increasing elevation. The negative effect of this temperature gap on pollination could be compensated by plastically-prolonged flower life spans at higher elevations, increasing the probability of pollination. In a tightly temperature-controlled study, the flowering phenology adjustment and flower longevity compensation hypotheses were investigated in an alpine species in the Andes of central Chile. The snow free period varied from 7 to 8.2 months over 810 m elevation. Temperatures were suitable for growth on 82–98% of the snow free days. Flowering onset was temporally displaced at the rate of 4.6 d per 100 m increase in elevation and flowering was more synchronous at higher elevations. Flowering phenology was adjusted over elevation. The latter was manifest in thermal sums tending to decrease with elevation for population flowering onset, 50% flowering, and peak flowering when the lower thermal limit for growth (TBASE) was held constant over elevation. For TBASE graded over elevation so as to reflect the growing season temperature decline, thermal sums did not vary with elevation, opening the door to a possible elevational decline in the thermal temperature threshold for growth. Potential flower longevity was reduced by passive warming and was more prolonged in natural populations when temperatures were lower, indicating a plastic trait. Pollination rates, as evaluated with the Relative Pollination Rate index (RPR), when weighted for differences in floral abundance over the flowering season, declined with elevation as did fruit set. Contrary to expectation, the life-spans of flowers at higher elevations were not more prolonged and failed to compensate for the elevational decrease in pollination rates. Although strong evidence for phenological adjustment was forthcoming, flower longevity compensation did not occur over Oxalis squamata’s elevational range. Thus, flower longevity compensation is not applicable in all alpine species. Comparison with work conducted several decades ago on the same species in the same area provides valuable clues regarding the effects of climate change on flowering phenology and fitness in the central Chilean alpine where temperatures have been increasing and winter snow accumulation has been declining.

Induced cleistogamy: A strategy for reproductive assurance in Murdannia nudiflora (Commelinaceae)

Botany ◽  
2019 ◽  
Vol 97 (10) ◽  
pp. 547-557
Author(s):  
V. Veena ◽  
Santhosh Nampy
Keyword(s):  
Mating Systems ◽  
Vegetative Reproduction ◽  
Environmental Parameters ◽  
Atmospheric Temperature ◽  
Maximum Efficiency ◽  
Flower Longevity ◽  
Reproductive Assurance ◽  
Insect Pollinators ◽  
Weedy Species ◽  
Murdannia Nudiflora

Murdannia nudiflora (L.) Brenan is a day flower that is dependent on entomophilous pollination. Despite the lack of pollinator attractants and its short flower longevity, M. nudiflora shows high rates of fecundity, which lead to their rapid dispersal. In addition to monitoring the vegetative reproductive methods and the effect of select environmental parameters (atmospheric temperature, relative humidity, and precipitation rates) in M. nudiflora, we evaluated mating systems in this species via artificial crosses. This species has evolved to undergo autogamy to ensure reproductive success when pollinators are insufficient; cleistogamous flowers are produced for optimal pollinator activity when environmental conditions are unfavorable. The number of cleistogamous flowers produced was found to be positively correlated with humidity and precipitation rates, and negatively correlated with temperature. In addition, it was found that high humidity and precipitation always hinder insect pollinators. Therefore, the combination of vegetative reproduction, entomophily, and cleistogamous self-pollination helps this weedy species to propagate with maximum efficiency. Murdannia nudiflora employs pre-anthesis cleistogamy as a mating strategy for reproductive assurance while retaining mechanisms that promote out-crossing.

Fluoride Injury to Cut `Samantha' Roses May Be Reduced by Pulsing with Calcium Nitrate

HortScience ◽  
1990 ◽  
Vol 25 (10) ◽  
pp. 1270-1271 ◽  
Author(s):  
Caroline H. Pearson-Mims ◽  
Virginia I. Lohr
Keyword(s):  
Weight Gain ◽  
Calcium Nitrate ◽  
Flower Longevity ◽  
Fresh Weight ◽  
Flower Opening ◽  
Visual Symptoms ◽  
Flower Quality ◽  
Nitrate Pulse ◽  
Solution Uptake ◽  
Preservative Solutions

Cut `Samantha' roses (Rosa hybrida L.) were placed in deionized water or a 20-mm Ca(NO3)2 pulsing solution for 72 hours. Flowers then were held in preservative solutions containing 0 or 4 mg fluoride/liter. Fresh weight gain, solution uptake, degree of flower opening, and flower longevity were reduced in the presence of fluoride in the holding solution. Visual symptoms of injury and reduced flower quality also were noted in treatments with fluoride. Pulsing improved fresh weight gain and degree of opening of flowers held in solutions containing fluoride. Pulsing also delayed the onset of visual symptoms of fluoride injury. Water uptake for flowers that were pulsed and exposed to fluoride was not different from uptake for flowers exposed to fluoride alone. Flower longevity for roses in all treatments was increased by using the calcium nitrate pulse, but pulsed flowers in fluoride did not survive as long as the control flowers.

Contributions to the Knowledge of the Lichen Flora of the Himalayas III. On Lecanora Somervellii Paulson (Lichenized Ascomycotina, Lecanoraceae)

1992 ◽  
Vol 24 (2) ◽  
pp. 111-117
Author(s):  
W. Obermayer ◽  
J. Poelt
Keyword(s):  
Usnic Acid ◽  
Type Material ◽  
Lemon Yellow ◽  
High Altitudes ◽  
Yellow Colour ◽  
Alpine Species ◽  
The Alps ◽  
High Himalayas ◽  
Very High ◽  
Lichen Flora

Abstract The lichen Lecanora somervellii Paulson, first described from the northern slopes of Mt Everest in Tibet, has been collected at four other localities in the High Himalayas, at altitudes between 3750 and 5540 m. As the type material appears to be missing, a neotype is designated here. The species has an unusual lemon yellow colour due to the pigment calycin; this compound is in addition to usnic acid, which is widespread in Lecanora. Lecanora somervellii is otherwise very similar in essential characters to the complex including Lecanora concolor Ram. and L. orbicularis (Schaerer) Vainio, high alpine species well-known, for example, from the Alps. It is supposed, that L. somervellii is derived from this aggregate by the production of calycin (in addition to usnic acid), which acts as an additional protective pigment at these very high altitudes.

scholarly journals Exogenous 5-azaCitidine accelerates flowering and external GA3 increases ornamental value in Iranian Anemone accessions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vahideh Yari ◽  
Zeynab Roein ◽  
Atefeh Sabouri
Keyword(s):  
Morphological Characteristics ◽  
Flower Longevity ◽  
Cut Flowers ◽  
Stem Height ◽  
Flowering Stage ◽  
Potted Plants ◽  
Dormancy Period ◽  
Treatment Conditions ◽  
Number Of Leaves ◽  
Pre Treatment

AbstractThe Anemone genus is a tuberous geophyte which undergoes a dormancy period during unfavorable environmental conditions for growth. Five species of the Anemone genus naturally grow in several regions of Iran. The diverse uses of Anemone in gardens for landscaping, cut flowers, and potted plants indicate its high ornamental potential. Its dormancy and flowering are influenced by various factors. The present paper was conducted to explore the flowering behavior of Anemone accessions in response to different pre-treatments. For this purpose, tubers of 18 Anemone accessions (A. coronaria and A. biflora) were collected from natural regions of six provinces in Iran. These tubers were subjected to different conditions of non-chilling (20 °C, 90 days), chilling (4 °C, 90 days), GA3 (150 mgL-1; 24 h), and 5-azaCitidine (5-azaC; 40 µM; 24 h) prior to the cultivation. Most of the accessions were able to enter the flowering stage without chilling. The shortest period for the sprouting of tubers (16.89 ± 7.83 days) belonged to 5-azaC pre-treatment. In addition, this treatment accelerated the flowering time (about 30 days earlier) and diameter of the stem, bud, and flower. Morphological characteristics, such as stem height, number of leaves, bud, and petal and the longevity of flowers on the plant were significantly affected by GA3 pre-treatment. Our results indicated a positive correlation between flower length, stem height, and stem diameter with flower longevity under different pre-treatment conditions. The present study demonstrated that accessions Anm3, Anm12, and Anm18 had ornamental values higher than the population mean across four conditions.

scholarly journals What ecological factors favor the shift from distyly to homostyly? A study from the perspective of reproductive assurance

2017 ◽  
Vol 11 (4) ◽  
pp. 645-655 ◽  
Author(s):  
Xian-Feng Jiang ◽  
Xing-Fu Zhu ◽  
Ling-Ling Chen ◽  
Qing-Jun Li
Keyword(s):  
Ecological Factors ◽  
Reproductive Assurance

Reproductive success of Acacia longifolia (Fabaceae, Mimosoideae) in native and invasive populations

2015 ◽  
Vol 63 (5) ◽  
pp. 387 ◽  
Author(s):  
Marta Correia ◽  
Sílvia Castro ◽  
Susana Rodríguez-Echeverría
Keyword(s):  
Reproductive Success ◽  
Seed Size ◽  
Fruit Set ◽  
Lower Number ◽  
Open Pollination ◽  
Native Range ◽  
Reproductive Assurance ◽  
Acacia Species ◽  
Self Compatibility ◽  
Selfing Ability

The reproductive biology of exotic species affects their capacity to become naturalised and invasive in non-native areas. Selfing is a common trait in many invasive plants probably because it provides reproductive assurance under low availability of pollination vectors and sexual partners. Nonetheless, the predominantly self-incompatible Australian Acacia species are among the most aggressive plants worldwide. To address whether there have been changes in selfing ability and natural reproductive success of A. longifolia during invasion, we compared one population in the invaded area (Portugal) with one population in the native range (Australia). We specifically assessed floral traits, fruit set and offspring traits for selfing and open-pollination treatments. Within each pollination treatment, no differences were found between areas, suggesting that the level of self-compatibility has not changed during invasion. However, the number of aborted seeds and seed size were significantly different between pollination treatments in Australia but not in Portugal. There were significant differences in the number of seeds per pod and in seed weight between ranges. A lower number of aborted seeds, a higher number of fully developed seeds and a greater seed size were found in the invaded area for both pollination treatments. In spite of the low selfing ability of A. longifolia in the invaded area, there was an increase in the quantity and size of the seeds produced in the new region, even for self-pollinated fruits, which might contribute to A. longifolia invasiveness.

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