Cucumber Fruit Size and Shape Variations Explored from the Aspects of Morphology, Histology, and Endogenous Hormones

Abstract

Fruit size and shape are important qualities and yield traits in cucumber (Cucumis sativus L.), but the factors that influence fruit size and shape remain to be explored. In this study, we investigated the dynamic changes of fruit size and shape from the aspects of morphology, cellular levels and endogenous hormones for nine typical cucumber inbred lines. The results show that fruit length had a strong positive correlation to the cell number in the longitudinal section of fruit throughout the four stages of 0, 6, 12, and 30 DAA (days after anthesis). However, the significant negative correlations were found between fruit length and the fruit cell size at 12 and 30 DAA. Furthermore, fruit diameter was positively correlated to the cell number in the cross section at all the investigated fruit growth stages. The indole-3-acetic acid (IAA) content showed significant positive correlations to the fruit length at all fruit growth stages of −6, −3, 0, 3, 6, 9 and 12 DAA, but IAA content and fruit diameter showed significant negative correlations for all the stages except for at −6 DAA. The trans-zeatin riboside (tZR), zeatin (ZT), gibberellic acid (GA3) and jasmonic acid (JA) content had a positive or negative correlation with fruit length or diameter only at certain stages. Neither fruit length nor diameter had significant correlations to abscisic acid (ABA) content. These results indicate that variations in fruit size and shape of different cucumber inbred lines mainly result from the differences in fruit cell number and endogenous IAA content. The present work is the first to propose cucumber fruit size and shape changes from the combined aspects of morphology, cellular levels, and endogenous hormones.

Effects of Endogenous Hormones and Sugars on Fruit Size Driven by Cell Division between Korla Fragrant Pear and Its Bud Mutation

“…ZR content of Zaomeixiang pear was always greater than that of Korla fragrant pear during whole-cell division. This is consistent with the results of studies of fruit size in orange and pear (Liu et al, 2020;Pang et al, 2017). ZR can promote the input and accumulation of photoassimilates, which may cause Zaomeixiang pear to have a greater sorbitol content than Korla fragrant pear.…”

“…Cell division is affected by endogenous hormones and sugars. Endogenous hormones are important signaling substances synthesized in plants, and are involved in the regulation of cell division and expansion (Liu et al, 2020). As the main metabolic material, sugars provide raw materials for plant growth and respond to the regulatory effects of endogenous hormones (Simona et al, 2020).…”

The NAC transcription factor ClNAC68 positively regulates sugar content and seed development in watermelon by repressing ClINV and ClGH3.6

“…Plant hormones and hormone signal transduction pathways play important roles in regulating seed germination, plant growth, development, and fruit ripening 9 . In cucumber, the IAA content was found to show a positive correlation with fruit size 10 . In peach, suppression of PpYUC11 was found to decrease the IAA level and result in increased fruit fitness 11 .…”

Light intensity affects the coloration and structure of chimeric leaves ofAnanas comosus var. bracteatus

“…Leaf samples of each treatment were harvested and sliced by double-sided blades, mounted in water, and viewed immediately. The method of paraffin sections is described in more detail by Liu et al [30]. The observation and photographical documentations of the marginal and central parts of the chimeric leaves were carried out using a photomicroscope (Leica DM1000, Leica Microsystems, Ltd, Germany).…”