Differential Responses of Commercial Tomato Rootstocks to Branched Broomrape

Rida Draie

doi:10.12691/plant-5-1-3

Abstract

Gravely infestation of tomato fields by Broomrape (Phelipanche ramosa) is growing in the Mediterranean basin. Completely devoid of chlorophyll, the root-parasite is entirely dependent on the host-derives and successively competes with the sink organs of infected plants. No efficient and economic control means has been found. Tomato grafting on resistant rootstocks is a very efficient solution for soil parasites control. The selected tomato rootstocks for their resistance to the soil parasites could be also a source of resistance to the Broomrape. In this work, we screen different commercial tomato rootstock genotypes for their resistance to Phelipanche ramosa. In the greenhouse conditions, we show that rootstocks are different in the degree of susceptibility to Broomrape. Attachment number, emergence number, and fresh matter of parasitic broomrapes are affected by rootstock genotype. A significant impact of the parasitism onto the dry weight of all infected tomato rootstocks with variable degree is observed. Energy, Groundforce and Eldorado which have less of attachment number and emergence number successively appear interesting for our objective.

Highlights

Tomato (Solanum lycopersicum L.) is an important vegetable crop at mondial level
After 7-day conditioning, all the tested GR24 concentrations from 0.1 to 10 mg L-1 triggered high germination rates, up to the optimal value of 99% with GR24 1 ppm (Table 2). This preliminary test was essential to prove the good ability of the broomrape seeds to germinate in the presence of germination stimulants. This seed set could be used for the screening of the tomato rootstocks in greenhouse
This study proposes to evaluate the behavior of many commercial tomato rootstocks resistant to soil-borne pathogens provided from international seed-bearers for their resistance to the branched broomrape

Summary

Introduction

Tomato (Solanum lycopersicum L.) is an important vegetable crop at mondial level. Infestation of tomato fields by branched and Egyptian broomrapes (Phelipanche ramosa, P. aegyptiaca L., respectively) is growing in the arid and semi-arid environments, especially in the Mediterranean basin. Tomato is the most affected crop being the prominent host of this parasite. Yield losses in tomato fields can reach 25% to 75% in heavy-infested fields [1,2,3]. Mauromicale et al, [4] showed that the broomrape causes a significant reduction of tomato photosynthetic capacity, generating a significant loss of their aerial organs biomass. The danger of this parasite comes from the long viability of its tiny seeds (0,2-0,3 mm and 3 μg) in the ground, which exceed at least the ten years, and of its very high rate of multiplication (100000 seeds plant-1), [5]. The majority of the damage on the host is caused during the underground growth of the parasite and no practical methods to control it effectively [6]

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