Tetraploid Induction by Colchicine Treatment and Crossing with a Diploid Reveals Less-Seeded Fruit Production in Pointed Gourd (Trichosanthes dioica Roxb.).

Jahidul Hassan,Yuki Mizunoe,Ikuo Miyajima,Wasimullah Zaland,Yukio Ozaki,Kaori Sakai

doi:10.3390/plants9030370

Abstract

Pointed gourd (Trichosanthes dioica Roxb.) (2n = 2x = 22) is a dioecious cucurbit vegetable and green fruit that is edible after cooking. Consumers prefer to consume seedless or less-seeded fruit because seeds are unpalatable due to their hard coats. Therefore, the cross compatibility between the diploid and induced tetraploid will be helpful for seedless or less-seeded fruit production. Thus, the present study was conducted using mature seeds that were immersed in 0.05%, 0.1%, and 0.5% colchicine for 24, 48, and 72 h to induce tetraploids. These tetraploids were used as parents (male or female) in the inter-ploidy and intra-ploidy crosses. A flow cytometric analysis confirmed the induction of three tetraploids at 0.5% colchicine for 48 and 72 h soaking periods. Among these, two (2) females and one (1) male were differentiated after flower initiation. Crossing between the tetraploid’s maternal and diploid paternal parent (4x × 2x), which were revealed to be compatible, resulted in a similar fruit set rate and shape as those of the diploid. In addition, a seed number of 4x × 2x produced fruits that were drastically reduced to 1.8 seeds per fruit, whereas the natural diploid fruits had 26.4 seeds per fruit. These findings suggest that colchicine-induced tetraploid females are important genetic resources for less-seeded fruit production. The genetic stability of tetraploid clones can easily and effectively be maintained by vine cutting for advanced uses.

Highlights

Pointed gourd (Trichosanthes dioica Roxb.) is one of the most important cucurbit summer vegetables in India and Bangladesh
Indetermine this study, their we examine the effectiveness of colchicine treatment under different information will help plant breeders extend their genetic improvement studies advanced and exposure times for tetraploid induction in pointed gourd seeds
There was no consistent trend observed for concentrations or the duration of colchicine treatment on the germination and survival rate of pointed gourd seedlings

Summary

Introduction

Pointed gourd (Trichosanthes dioica Roxb.) is one of the most important cucurbit summer vegetables in India and Bangladesh. It is a diploid type with a chromosome number of 2n = 2x. = 22, where 11 bivalents are observed in the pollen’s mother cells [1] It is a dioecious type, where the male and female flowers are carried on separate plants. Each fruit contains more than 20 seeds and becomes harder at 3–4 weeks after pollination (Figure 1). At this point, it loses consumer acceptance because of its unpalatable seeds with hard coats. Parthenocarpy induction approaches might be able to solve this problem

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Conclusion