Pollen tube growth and fruit set in quince (Cydonia oblonga Mill.)

Abstract

Aim of study: To determine the self-compatibility level of eight quince cultivars.Area of study: The region of Belgrade (Central Serbia).Material and methods: Pollen tube growth in vivo and fruit set in two pollination variants (self- and open-pollination) were studied in eight quince cultivars. The quantitative parameters of pollen tube growth (average number of pollen tubes in the upper and middle third of the style, base of the style and in the ovary; the dynamics of pollen tube growth through these parts of the pistil) was determined using the fluorescence microscopy.Main results: The parameters of pollen tube growth and fruit set were primarily dependent on the genotype and variants of pollination. All studied parameters were significantly higher in the open-pollination variant compared with the self-pollination in all cultivars. In the self-pollination variant, ʻLeskovackaʼ and ʻVranjskaʼ had the highest number of pollen tubes that penetrated the ovary (2.10 and 0.54 in average, respectively), as well as the largest percentage of pistils with the penetration of pollen tubes in the nucellus of ovules six days after pollination (40.09% and 14.74%). Also, they had the highest percentage of initial fruit set (17.01% and 28.52%) and final fruit set (9.32% and 9.86%). Based on this, ʻLeskovackaʼ and ʻVranjskaʼ can be classified as self-compatible cultivars, while the others are self-incompatible.Research highlights: The majority of quince cultivars were self-incompatible. When establishing new orchards with these cultivars, care should be taken about the choice of pollenisers in order to achieve high yields.

Identification of self-incompatibility alleles in Quince (Cydonia oblonga Mill.)

“…These results suggest that quince can exhibit both self-incompatibility and self-compatibility. This finding is consistent with previous studies by Tatari et al [ 24 ] and Radović et al [ 25 ], which reported that quince can exhibit different levels of self-incompatibility in various cultivars. Radović et al [ 25 ] found that ’Leskovacka’ and ’Vranjska’ were self-compatible cultivars, while the others were self-incompatible.…”

“…This finding is consistent with previous studies by Tatari et al [ 24 ] and Radović et al [ 25 ], which reported that quince can exhibit different levels of self-incompatibility in various cultivars. Radović et al [ 25 ] found that ’Leskovacka’ and ’Vranjska’ were self-compatible cultivars, while the others were self-incompatible. In contrast, the recent study by Radović et al [ 26 ] found that incompatible pollen tubes were present in both self-pollination and open pollination, andthat only ’Leskovacka’ and ’Vranjska’ were self-compatible.…”

“…The study recommends using different cultivars with proper overlap at flowering time to improve and increase the yield of quince. Radović et al [ 25 ] suggested that care should be taken about the choice of pollenisers when establishing new orchards with self-incompatible quince cultivars.…”

Incompatible pollen tubes in the quince style and their impact on fertilization success

“…An earlier study on the same cultivars included a detailed analysis of the number of pollens tubes in the pistil and style, but also of the dynamics of pollen tube growth by pistil regions. Based on these results, 'Leskovacka' and 'Vranjska' were found to be self-compatible, while other cultivars ('Morava', 'Pazardzijska', 'Hemus', 'Asenica', 'Portugal' and 'Triumph') were self-incompatible (Radović et al, 2020). The study of incompatible pollen tubes in quince is a continuation of previous studies with the aim of analysing in detail the phenomenon of incompatibility in quince in two pollination modes (self-pollination and open pollination).…”

“…The cultivar is considered self-compatible if the pollen tubes during self-pollination reach the ovary in at least 25-30% of the pistils (Lopez et al, 2001). Based on the above, the cultivars 'Vranjska' and 'Leskovacka' are classified as self-compatible, while the other cultivars are classified as self-incompatible (Radović et al, 2020). Milatović and Nikolić (2007) and Milatović et al (2013b) consider as self-fertile those apricot cultivars in which at least one pollen tube reached the pistil in most of the analysed pistils.…”