Sex distinction of asparagus by loop-mediated isothermal amplification and observation of seedling phenotypes

Abstract

Asparagus (Asparagus officinalis L.) is a dioecious plant. In general, male and female plants are used for open-field culture and intensive cultivation, respectively. Farmers distinguish between the sexes by observing the form of the flower organs. However, because flowering begins 2-3 years after planting, the sexes cannot be differentiated at transplantation by using this method, and planting of an all-male population is not possible. In this study, the usefulness of loop-mediated isothermal amplification (LAMP), a simple method of gene amplification, for sex distinction at the DNA level was determined. In addition, the phenotypic differences in seeds and seedlings of male and female plants were investigated for application as a method of early sex distinction. By using the LAMP method, the sex could be correctly identified in 100% of the seedlings, suggesting that this method is effective for sex distinction at the gene level. Principal component analysis was conducted with 11 selected parameters after investigating the seeds and seedlings of both male and female plants. The results revealed that male plants tend to have many stalks or cladophylls and female plants tend to have large plant forms, suggesting that the sexes can be distinguished by the external appearance of the seedlings before planting. LAMP and observation of the seedling phenotypes could be useful methods of sex distinction for increasing the efficiency of asparagus breeding.

Productive Differences between Male and Female Plants in White Asparagus Production Using the Rootstock-planting Forcing Culture Technique

“…DNA was extracted with water by grinding the cladophylls with a ceramic ball in a plastic tube. The sex of each plant was determined by loop-mediated isothermal amplification (LAMP) according to Shiobara et al (2011) using a Loopamp reagent kit (Eiken Chemical, Tokyo, Japan). A total of 25 male and 25 female seedlings were then transported to each of the eight experimental sites in Japan (Table 1) …”

“…Therefore, several early sex determination procedures for seedlings have been developed (Ii et al, 2012;Kanno et al, 2014;Shiobara et al, 2011), which have made it easier to distinguish male and female plants at the seedling stage. To ensure the uniformity of the transplants, the seedlings were cultivated collectively, and the male and female plants were identified before transplantation.…”

Combination of low oxygen and high carbon dioxide treatmentsalters sprouting of white asparagus

“…Seedlings were transplanted to black polyethylene pots (90 mm diameter and 360 mL volume) on 11 June 2014 and then to pots (10.5 mm diameter and 570 mL volume) on 12 September. To control for differences between male and female asparagus plants due to sprouting (Koizumi et al, 2002), the sex of the plants was determined by examining the flowers and/or by loop-mediated isothermal amplification method (Shiobara et al, 2011). Three male and 3 female plants were used for each treatment, although 2 treatments were applied to 4 male and 2 female plants.…”

A Review of Detection Methods for the Plant Viruses

“…In addition, it has been used to determine sex of asparagus, genetically modified organisms (GMOs), and Phytoplasmas (Lee et al, 2009;Shiobara et al, 2011;Tomlinson, 2010). The RT-LAMP has been developed for simple monitoring of RNA viruses including PVY and PLRV (Ju, 2011;Nie, 2005).…”