Pollen tube kinetics is affected by temperatures during the flowering period

14 Aug 2023
2237

Environmental conditions during the cherry flowering season are a crucial factor influencing seed set and, consequently, fruit set. The potential impact of this factor on reproductive success is likely to increase considering the effects induced by global warming. 

In fact, for the sweet cherry, the Mediterranean area represents a borderline environment for its cultivation, and a further increase in temperatures could lead to a reduction in the area devoted to this crop. Pollen tube dynamics, which includes the time required for pollen germination and the pollen tube growth rate, is significantly affected by temperature.

Pollen germination is a highly variable parameter, whether it occurs between different species or between cultivars within the same species. In general, the optimal temperature range for pollen germination coincides with the average temperatures of the flowering period, and this relationship has been demonstrated in several fruit species. 

Pollen tube growth, on the other hand, is promoted by temperatures in both herbaceous and woody species.  The impact of temperature on pollen tube kinetics has been studied previously, but there is a lack of knowledge on how temperature affects pollen tube dynamics, particularly in terms of the population of male gametophytes that are able to reach the base of the style. 

Therefore, the hypothesis of temperature influence on the male gametophyte population can be considered plausible, but still not supported by scientific data. Therefore, the study conducted in experimental orchards in Zaragoza (Spain) by researchers from the Fruit Tree Crops Unit aimed to evaluate the impact of temperature on pollen kinetics in cherry trees

Specifically, two cultivars with different levels of adaptation to temperature were compared as pollen donors. The cultivar known as 'Sunburst' originated in Canada and can be counted among the northern European cultivars. The cultivar 'Cristobalina,' on the other hand, is native to southeastern Spain and has adapted to thrive in warmer climatic conditions. 

The effects of temperature were evaluated by experiments conducted in temperature-controlled chambers and in the field using plastic structures to cover the trees. The results show that optimal temperatures for pollen germination, pollen tube kinetics and pollen dynamics exhibit variation, indicating the presence of distinct regulatory mechanisms.

Increasing temperature resulted in a decrease in germination rate, but also in an acceleration of pollen tube growth rate within the style. In both genotypes, higher temperature caused a decrease in pollen germination while promoting the growth rate of pollen tubes.

The pollen tubes of Cristobalina showed a higher rate of reaching the base of the style of all flowers, compared to Sunburst, at the three temperatures examined (10°C, 20°C and 30°C). It is worth noting that the pollen tube growth rates of the Cristobalina species remained fairly constant at both 20°C and 30°C.

In contrast, the Sunburst species showed a significant increase in its growth rate precisely at 30°C. This variation suggests that adaptation to pollen donor temperature plays an important role in determining the observed effects. The observed decline in germination rates of both paternal genotypes with increasing temperature can potentially be attributed to the broader adaptation of sweet cherry to colder temperatures. 

The results of this study suggest that there is variation in genetic response to temperature during the reproductive phase. This variation may have significant implications for the ability of plant species to adapt to sudden changes in temperature.

Sourcee: Hedhly, A., Hormaza, J.I. and Herrero, M. (2004), Effect of temperature on pollen tube kinetics and dynamics in sweet cherry, Prunus avium (Rosaceae) . Am. J. Bot., 91: 558-564. https://doi.org/10.3732/ajb.91.4.558

Melissa Venturi
University of Bologna (IT)


Cherry Times - All rights reserved

What to read next

Energy and agriculture: protection and agro-photovoltaics panels for cherry orchards

Planting systems

12 Jul 2024

One of the great advantages of this new technology is that thanks to its height (4.5 metres) it acts as a physical protection against damage caused by rain and hail, greatly reducing fruit splitting, which generates losses in the millions every year.

Analysis of fungal diversity responsible for cherry fruit rot in Shandong province, China

Crop protection

11 Nov 2024

Pathogenicity tests showed that all isolated species could cause fruit infections, though with varying levels of aggressiveness. Among them, Diaporthe eres displayed the highest virulence followed by Fusarium incarnatum and Botryosphaeria dothidea.

In evidenza

The Chilean model and prospects for cherry growth in Peru

Production

12 Dec 2025

In the last decade, Chile turned cherries into a premium export worth over US$ 1.8 billion, driven by ideal climate, advanced technical management and booming Chinese demand. Andean areas of Peru show potential, but would require infrastructure and adapted strategies.

Pre-harvest treatments with chitosan and salicylic acid to improve the quality and storability of sour cherries

Quality

12 Dec 2025

A Ukrainian study shows that a pre-harvest treatment with chitosan and salicylic acid extends sour cherry shelf life up to 30 days, reducing weight loss, defects, and microbial contamination. It enhances fruit storage, quality and marketability post-harvest.

Tag Popolari