Screening wild and cultivated cucurbits against root knot nematode to exploit as rootstocks for grafting in cucumber

Abstract

Yield of mono-cropped cucumber (Cucumis sativus L.) is reduced by root knot nematode (Meloidogyne incognita Kofoid and White). Use of resistant rootstocks in grafting may overcome the problem. Cucurbitaceous species were screened against root knot nematode to evaluate their use as rootstocks in grafting. Inoculation was with nematodes @ 2 J2·g-1 (J2 = second stage juvenile) of soil in pot culture at the 1 to 2 true leaf stage, 45 days after inoculation, plants were uprooted and observations made to calculate Root Knot Nematode Index (RKI). Cucurbita moschata, Cucumis metuliferus, Citrullus colocynthis and Cucumis callosus were resistant having a RKI-2. Cucurbita ficifolia, Cucurbita maxima, Cucumis melo sub sp. agrestis were moderately resistant with a RKI-3. Total phenols content in roots indicates plant resistance to M. incognita. Cucumis metuliferus had the highest mean total phenols content (16.98 mg·g- 1 of root) followed by Citrullus colocynthis (16.08 mg·g-1 of root) and Cucurbita moschata (15.37mg·g-1 of root). Resistant rootstocks possessed higher peroxidase and PPO activity than susceptible ones. Cucumis metuliferus had the highest value of peroxidase and PPO activity (3.83 OD·min-1·g-1 of root and 3.67 OD·min-1·g-1 of root) followed by Citrullus colocynthis (3.26 and 3.63 OD·min-1·g-1 of root), Cucumis callosus (3.02 and 2.98 OD·min-1·g-1 of root) and Cucurbita moschata (2.93 and 2.94 OD·min-1·g-1 of root). Cucumber scions, ‘Green Long’ and ‘NS 408’ had lower peroxidase and PPO activity of 0.64 and 1.42 OD·min-1·g-1 and 0.57 and 1.31 OD·min- 1·g-1 of root, respectively. Resistant and moderately resistant cucurbitaceous species may be used for further studies possibly leading to improved yield.

Assessment of Yield Losses due to Meloidogyne incognita on Cucumber (Cucumis sativus L.)

“…The yield of cucumber was found to be higher with the application of nematicide carbofuran at 2kg.a.i./ha. A significant reduction in the yield of cucumber in untreated plots was mainly attributed to direct damage of the root system by the feeding activities of root knot nematode (M. incognita) [3].…”

“…In India, salad is incomplete without this green fruit. In India, the area and production under cucumber is 116 ha and 1608 MT per ha (NHB 2021-2022 First Advance estimates)" [1,2] The nematode causes plant damage by directly eating through the root system of an infected plant and altering intake of water and nutrients, impairing photosynthesis [3,[4][5][6]. When M. incognita is present, field-grown cucumber yields can decrease by 25% annually [7].…”

Inevitable Role of Grafting in Improvement of Cucurbitaceous Crops: A Review

“…In order to find resistant rootstocks of cucurbitaceous species for grafting cucumbers against root-knot nematode, Punithaveni et al (2015) did a study where, Citrullus colocynthis and Cucumis metuliferus were found to have resistant reactions with a root knot index (RKI) of 2. They were backed by a related screening study of cucurbitaceous species against root-knot nematode conducted by Thangamani et al (2018) to assess their suitability as rootstocks in grafting. Cucurbita moschata, Cucumis metuliferus, Citrullus colocynthis and Cucumis callosus were found to be resistant having an RKI-2.…”

Plant growth and quality of cucumber grafted with Lagenaria siceraria in soil infested with nematodes

“…The forgoing has led development of ecological alternatives such as crop rotation, cover crops, resistant varieties, biological control and grafted plants (Ban et al, 2014;Singh and Phulera, 2015). Some species tolerant to M. incognita are of genus Cucurbita, Citrullus and Cucumis (Punithaveni et al, 2015;Thangamani et al, 2018). The species Lagenaria.…”