A Novel Graft between Pac Choi (Brassica rapa var. chinensis) and Daikon Radish (Raphanus sativus var. longipinnatus)

Tian Gong,Jeffrey Brecht,Zachary Ray,Kylee Butcher,Xin Zhao,Zachary Black

doi:10.3390/agronomy10101464

Abstract

Vegetable grafting has primarily been used in the commercial production of high-value crops in the Solanaceae and Cucurbitaceae families. In this study, we explored the feasibility of making a novel graft between pac choi (Brassica rapa L. var. chinensis) and daikon radish (Raphanus sativus L. var. longipinnatus) to create a plant with harvestable pac choi leafy vegetable above-ground, and a daikon radish taproot below-ground. ‘Mei Qing Choi’ pac choi (scion) was grafted onto ‘Bora King’ daikon radish (rootstock). Grafted pac choi–daikon radish plants did not show a decrease in SPAD value, canopy size, leaf number, leaf area, or above-ground weight compared with self-grafted pac choi plants. However, taproot formation was reduced in grafted pac choi–daikon radish plants, as shown by decreased taproot length, diameter, fresh weight, and dry weight compared with non- and self-grafted daikon radish plants. Surprisingly, grafting with radish increased the photosynthetic rate of the pac choi. This pilot study demonstrated the potential of creating a new pac choi–daikon radish vegetable product to help save growing space and minimize waste at consumption, as pac choi roots are not eaten and radish leaves are usually discarded. The inter-generic grafting between B. rapa var. chinensis and R. sativus var. longipinnatus could also provide a unique model system to help elucidate scion-rootstock synergy and above- and below-ground sink competition in horticultural crops.

Highlights

Grafting has become an effective practice in the production of high-value solanaceous and cucurbitaceous vegetables to help overcome biotic and abiotic stresses and improve crop productivity [1–3]
The relatively high survival rates of MQ/BK indicated good graft compatibility between ‘Mei Qing Choi’ pac choi and ‘Bora King’ daikon radish. Both the edible pac choi leafy green part of the plant and the radish taproot developed in MQ/BK (Figure 1A–C)
Successful grafts were produced between B. rapa var. chinensis and R. sativus var. longipinnatus in this study, resulting in a novel ‘pac choi–daikon radish’ product that may help save growing space and have added-value as perceived by farmers and consumers

Summary

Introduction

Grafting has become an effective practice in the production of high-value solanaceous and cucurbitaceous vegetables to help overcome biotic and abiotic stresses and improve crop productivity [1–3]. Scolymus) [6], grafting in other vegetable species beyond Solanaceae and Cucurbitaceae is generally not practiced commercially. Some attempts have been made to explore the feasibility of grafting vegetable plants in Brassicaceae. Oda et al [7] tested inter-varietal, inter-specific, and inter-generic grafting among cabbage An adhesive and hardener system was developed for making grafts between Chinese cabbage (scion) and turnip (rootstock) [8]. Chen et al [9] evaluated the survival rate of cabbage grafted onto Chinese kale (B. oleracea Alboglabra group) rootstocks and assessed the feasibility of using grafting to improve cabbage head quality

Methods

Results

Conclusion