Identify The Authenticity Of F₁ And BC₁ Between Lycopersicon Esculentum And Nematode Resistance Lycopersicon Peruvinanum

Cultivated tomatoes are sensitive to root-knot nematode.and the damage caused by the pest is severe. Up to now,there is no variety having the resistance to root-knot nematode obtained via ovule resuce in china.Plants of F₁ and BC₁ between Lycopersicon esculentum and Lycopersicon peruvinanum obtained via ovule rescue were investigated to identify their authenticity.The results of morphology and RAPD fingerprinting suggested that the plants of F₁ and BC₁ were the hybrids between L.esculentum and L.peruvinanum;CAPS marker showed that the interspecific hybrids had root-knot nematode resistance Mi gene.The results of pest resistance experiment in field showed that all the hybrids were resistant to root-knot nematode. It is concluded that the root-knot nematode resistance gene can be introduced to cultivated tomato via ovule rescue.Our study also provided reliable identification techniques for the material detection.Genomic in situ hybridization (GISH) is a powerful tool to study genome or chromosome in many plants.But it seldom employed in tomato in china. During the identification of F₁ between L.esculentum and L.peruvianum, A method for high quality chromosomes slides preparation was fumbled, and a routine for tomato GISH was set up. when the ratio between blocking DNA and probe DNA was low, it is impossible to distinguish the chromosomes coming from different parents;It can be done only when the block DNA exceeded the concentration of probe DNA by hundren and fifty fold.These results suggested that L.esculentum and L.peruvinanum share the high degree of homoeology sequence.Identification of the authenticity of hybrids by GISH was very difficult in present.