INTERSPECIFIC GRAFTS BETWEEN Solanum lycopersicum AND S. habrochaites AS AN ALTERNATIVE TO INCREASE FRUIT YIELD

Grafting is a technique that improves tomato productivity (Solanum lycopersicum L.) if the rootstock/scion combination is adequate. In Mexico, the seed of the rootstock is imported, it is expensive and, therefore, limited. In order to identify outstanding germplasm with potential as a rootstock, two experiments were established to evaluate 10 wild relative accessions from the cultivated tomato. The hypothesis was that there are wild germplasm accessions capable of increasing yield. Eight accessions of S. habrochaites Knapp & Spooner, two of S. pimpinellifolium L. and the commercial checks 'Maxifort' and 'Multifort' (S. habrochaites x S. lycopersicum) were evaluated as rootstocks, and 'El Cid' and 'Sun7705' as scions. A randomized complete block design with three replications and 10 plants per experimental unit were used, wherein the treatments consisted of the rootstock/graft combinations. Twelve variables were measured and statistical differences were observed between treatments in most of them. The outstanding rootstocks combined with 'El Cid' were the collections LA2409, LA1223, LA2158, LA1777, LA2167 and LA1576, these improved the yield in 17% average; LA2409, LA1223, GH08 and LA0373 with 'Sun 7705' increased productivity by 24% and surpassed commercial rootstocks by up to 41%. There are wild relatives of the cultivated tomato with potential to be used as a rootstock, since they improve fruit yield in comparison with the ungrafted and self-grafted plants. The accessions LA2409 and LA1223 showed stability in both scions.