Unilateral incongruity in crosses involving Lycopersicon pennellii and L. esculentum is distinct from self-incompatibility in expression, timing and location

摘要: Both interspecific and intraspecific mechanisms restrict the exchange of genes between plants. Much research has focused on self incompatibility (SI), an barrier, but barriers lags behind. We are using crosses betweenLycopersicon esculentum andL. pennellii as a model with which to study crossing barriers. The crossL. esculentum×L. is successful, reciprocal cross fails. Since can be successfully made in one direction not other, gross genomic imbalance or chromosomal abnormality precluded causes. showed that lack seed set observed pennellii×L. due inability pollen tubes grow more than 2–3 mm into style, whereas S1 show continued slow tube growth but, also, fail seed. These results indicate unilateral response barrier distinct from SI, differing SI timing location expression style. therefore suggest this theL. accurately referred “unilateral incongruity” (UI) rather incompatibility. Periclinal chimeras were used determine tissues involved UI. available female parent must beL. at either LI (layer 1) both LII 2) male observe UI similar seen cross. Pollinations mixture fromL. transgenicL. plants harboring pollen-specific GUS reporter gene marker ascertain whether species was modified possible means overcoming found no evidence communication two types enhance all growth.