Induction of tetraploidity with antimicrotubule agents in oriental melon (Cucumis melo var. Makuwa)

Abstract

Polyploidy induction is an important method for the innovation of germplasm resources because polyploid plants have superior characteristics to diploid ones. In this paper, oriental melon (Cucumis melovar. makuwa) tetraploids were induced by treating the apical meristem of seedlings with oryzalin, amiprophos-methyl (APM) and colchicine. The results showed that each of these three antimicrotubule agents could induce the formation of tetraploid oriental melon, but oryzalin and APM showed higher efficiencies of tetraploid induction. The efficiencies of tetraploid induction were highest (14.44%) when treated with 80 µmol·L−1APM for 6 days. Stomata characteristics were used to screen the treated plants for changes in ploid levels preliminarily. Subsequently, the changes in ploid levels were further confirmed by flow-cytometric analysis and chromosome counts of root tip cells. The comparison between diploids and tetraploids in fruit characteristics, reproductive characteristics, and postharvest storage qualities showed that the fruit of tetraploids had thicker flesh, higher total soluble solid (TSS) content and lower fruit shape index than diploids. The pollen grains of tetraploids were larger but showed lower vitality. In addition, a higher percentage of embryo-deficient seeds contributed to lower fertility. During postharvest storage, the fruit of tetraploids softened faster, had higher TSS content and lower respiration rate.

Artificial Polyploidization Enhances Morphological, Physiological, and Biological Characteristics in Melothria scabra Naudin

“…The efficiency of polyploidization achieved using oryzalin reached up to 15%. Similar to the current study, a polyploidization rate of up to 11.11% was obtained in oriental melon when oryzalin was used as an antimitotic agent [20].…”

“…For instance, in Cucumis melo L., polyploids were successfully induced using oryzalin, where the obtained polyploid plants exhibited substantial morphological changes in seeds, leaves, and stomata compared with the diploid mother plants [18]. A similar study on the same species reported a higher total soluble solid content in tetraploid fruits than in diploid fruits [20]. In Cucumis sativus L., polyploids were produced using colchicine that displayed larger leaf size, flower diameter, stoma size, pollen grains, and more chloroplast numbers in guard cells [21].…”

“…For example, a previous study reported a comparably high tetraploid induction efficiency (up to 14%) in Cucumis melo var. Makuwa, leveraging the application of oryzalin in conjunction with amiprophos-methyl (APM), when compared to traditional colchicine treatment [20]. Similarly, another study noted a higher effectiveness of chromosome doubling in Cucumis sativus L. through the utilization of oryzalin in contrast to trifluralin and colchicine in their study [16].…”

Autotetraploidization Alters Morphology, Photosynthesis, Cytological Characteristics and Fruit Quality in Sour Jujube (Ziziphus acidojujuba Cheng et Liu)

“…Polyploidization is one of the most effective approaches to improving fruit quality. In the previous studies, autotetraploid plants were shown to bear much larger fruit; for example, autotetraploid trees of apple [40] and banana [38], and autotetraploid plants of muskmelon [8,41]. On the contrary, the average fruit size of autotetraploid pears is approximately the same as that of diploids, though the autotetraploid fruit grows quicker than diploids during the early stages [10].…”