تقييم بعض الأصول لمقاومة لنيماتودا الحمضيات Tylenchulus semipenetrans

الملخص EN

Tylenchulus semipenetrans (Cobb) is worldwide the most important plant parasitic nematode of citrus, it causes a great economical losses, it has a worldwide distribution in citrus-growing regions.

Citrus breeding programs using resistant rootstocks treatment the local needs of producers and aim to integrate improved agricultural properties with resistance to citrus nematode.

This study was conducted to evaluate the resistance of citrus rootstocks to T.

semipentrans, the tested rootstocks were: Citrus aurantium, Poncirus trifoliate, (Citrus paradise Macf × P.trifoliata), Citrus volkameriana, Citrus sunki, Citrus reticulate.

Three months old rootstocks seedling grown in pots were infected with 5000 2nd stage of T.semipenetrans.

after six months the results were evaluated by the numbers of larvae \100cm3 soil, numbers of females\ 1g roots, total vegetable weight and total root weight per seedling.

The results showed that P.trifoliata was more resistant than other rootstocks, followed by C.

aurantium, C.

reticulate.