Penetration and Development of Meloidogyne javanica on Four Pistachio Rootstocks and Their Defense Responses

Abstract

Pistachio yield is annually reduced due to root-knot nematode infections. In order to evaluate its resistance to Meloidogyne javanica, three domestic pistachio rootstocks, namely, Badami, Ghazvini and Sarakhs, and a wild pistachio, Baneh (Pistacia atlantica subsp. mutica), were selected. Their response to the nematode infection was evaluated based on different plant and nematode indexes, 120 days post-inoculation (dpi). The penetration and development rate of nematode in roots of these four pistachio rootstocks were evaluated at different time points by acid fuchsin staining. Based on the measured indexes, Badami, Ghazvini, Sarakhs, and Baneh rootstocks ranked as susceptible, moderately resistant, moderately resistant, and resistant, respectively. The penetration rate of second-stage nematode juveniles (J2) into four rootstocks was discussed. The first “midstage” or swollen juveniles appeared at 4 dpi but to a lesser extent in Ghazvini, Sarakhs, and Baneh cultivars. The first females were seen in Badami at 21 dpi, in Ghazvini and Sarakhs at 35 dpi, and in Baneh at 45 dpi. Three types of defense responses were distinguished and characterized in the examined pistachio rootstocks: (i) a hypersensitive response (HR)-like reaction in the cortex in Ghazvini, Sarakhs, and Baneh root tips at 4 dpi and 6 dpi; (ii) an HR response, degrading J2 which induce giant cells in the vascular cylinder of all rootstocks, at 6 dpi and 10 dpi; and (iii) an HR response, degrading females and giant cells in the vascular cylinder of all rootstocks at 15 dpi onward. These observations open new fields of study in breeding programs of this crop.

Comparative analysis of antioxidant enzyme activity and defence responses in root‐knot nematode resistant and susceptible carrot cultivars

“…Evidently, HR occurred in TN-99-129 infected with RKNs, which is one of the characteristics of plant resistance. In line with these findings, an HR has been observed in resistant genotypes of other plants (Cabasan et al, 2014;Phan et al, 2018;Shekari-Mahoonaki et al, 2022), which prevents giant cell formation and further development of the nematode, leading to nematode death. In the present study, despite observing the HR-like reaction, the formation of feeding sites and nematode development occurred, but at a lower level compared to the susceptible variety.…”

“…However, the findings of Asadi‐Sardari, Mahdikhani‐Moghadam, Zaki‐Aghl, and Vetukuri (2022) and Shekari‐Mahoonaki et al. (2022) partly contradict this, as they reported that resistant cultivars disrupted nematode penetration and delayed RKN development in tomato and pistachio, respectively. Kumari et al.…”

Reaction of Commercial Cultivars of Kiwifruit to Infection by Root-knot Nematode and Its Biocontrol Using Endophytic Bacteria

“…Using resistance cultivars against plant parasitic nematodes has been one of the long-lasting approaches to fend off their attack. To reach this end, screening resistance plants is the main step not only to be used in the infested areas and areas with high potential for infection by RKN, but also for breeding programs or as a rootstock for a highly productive scion ( Saucet et al, 2016 ; Lesmes-Vesga et al, 2022 ; Mahoonaki et al, 2023 ). Also, the use of biological agents to control plant diseases has been the subject of much research due to the deleterious effect of chemical pesticides on human health and the environment.…”