Response of Malpighia emarginata active germplasm bank accessions to Meloidogyne enterolobii parasitism

Abstract

Malpighia emarginata is cultivated in almost all Brazil and is considered an important agricultural crop. The root-knot nematode Meloidogyne enterolobii has been described as a major threat to this crop, causing great production losses. Due to the scarcity of information about the severity of this parasite in M. emarginata plants in Brazil, this study investigated M. enterolobii resistance of ten M. emarginata genotypes from the active germplasm bank of Universidade Federal Rural de Pernambuco. The experiment was conducted adopting a completely randomized design in a factorial arrangement of 11 x 2 x 5, where M. emarginata cuttings were inoculated with 10,000 eggs in a greenhouse. After 150 days, plants were evaluated for the following parameters: gall index, egg mass index, number of eggs per root system, number of eggs per gram of root, and reproduction factor. The accessions showed different responses depending on host x pathogen interaction, from susceptibility to moderate tolerance. Accessions 027-CMF and 031-CMF were considered tolerant to the nematode and could be of great value in new breeding programs for resistance to M. enterolobii infection.

Resistance of Malpighia emarginata DC. Genotypes to Meloidogyne enterolobii Parasitism

“…The genotype 033-CMF showed a higher value of RWR, and also the higher GI and RF values, being the most susceptible of the observed genotypes. [11] evaluated the responses of eleven UFRPE-AGB M. emarginata genotypes to the parasitism of M. enterolobii. Regarding the variables RWS and RWR, the authors verified a significant difference only for the 028-CMF genotype, which exhibited the higher shoot and roots development of the evaluated genotypes and was classified as moderately resistant.…”

“…The experiment was conducted in a greenhouse located at the Agronomy Department of the Universidade Federal Rural de Pernambuco -UFRPE -Brazil. Twenty-two M. emarginata genotypes were utilized, of which twenty-one belong to the Active Bank of Germplasm (AGB) of the Carpina Sugarcane Experimental Station (E.E.C.A.C./UFRPE), located in the municipality of Carpina -PE and the variety BRS Sertaneja, which was selected due to its susceptibility to M. enterolobii [2,11].…”

“…A survey carried out in several irrigated perimeters in the São Francisco Valley Region, in northwestern Brazil, revealed a high percentage of infected M. emarginata trees, raising the concern that this phytonematode may turn the cultivation unfeasible, as it has happened to guava orchards in that same region [7][8][9]. Genotypes with resistance or tolerance to phytonematodes may be used as rootstocks, as a low cost and sustainable alternative to chemical control methods and, can easily be adopted by growers without environmental and sanitary risks [9][10][11]. The use of resistant rootstocks could provide effective control and significantly reduce the damages caused by M. enterolobii, allowing the recovery of infested areas [12].…”

Reaction of Psidium guineense and Psidium guajava genotypes to infection of Meloidogyne enterolobii

“…Psidium species, such as P. guineense and P. cattleyanum can be a source of resistance, which makes them important for the control of the damages caused by the nematode in question [12][13][14]. In the various studies aiming at the analysis of M. enterolobii infection on fruit plants, the period between inoculation and root extraction ranged from 60 to 135 days, with 120 days being the most common interval used for this stage [11][12][13]15], which makes the process of evaluation quite long and costly due to the crop handling costs of the plants. The objective of this work was to evaluate the response of genotypes of P. guinense and P. guajava to the plant parasitic nematode M. enterolobii, in an early manner, with an inoculation period of 60 days.…”

“…M. enterolobii represents a constant danger for cultivated plants. Its rapid dissemination and polyphagic habit, which enables it to live within roots and parasite a large number of species, such as ornamental plants, tobacco, soy, coffee, papaya, acerola, araçá, guava, weeds and various vegetables, make it a dif icult plague to control [8][9][10][11]. To this date, several studies have been carried out to ind genotypes of guava resistant to the infection of root-knot nematodes.…”