caa a22 4500 477053734 CHVBK 20180405111343.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF02152705 doi (NATIONALLICENCE)springer-10.1007/BF02152705 Unilateral incongruity in crosses involving Lycopersicon pennellii and L. esculentum is distinct from self-incompatibility in expression, timing and location [Elektronische Daten] [B. Liedl, S. McCormick, M. Mutschler] Both interspecific and intraspecific mechanisms restrict the exchange of genes between plants. Much research has focused on self incompatibility (SI), an intraspecific barrier, but research on interspecific barriers lags behind. We are using crosses betweenLycopersicon esculentum andL. pennellii as a model with which to study interspecific crossing barriers. The crossL. esculentum×L. pennellii is successful, but the reciprocal cross fails. Since the cross can be successfully made in one direction but not the other, gross genomic imbalance or chromosomal abnormality are precluded as causes. We showed that the lack of seed set observed in the crossL. pennellii×L. esculentum is due to the inability of pollen tubes to grow more than 2-3 mm into the style, whereas S1 crosses show continued slow pollen tube growth but, also, fail to set seed. These results indicate that the unilateral response is a barrier distinct from SI, differing from SI in the timing and location of expression in the style. We therefore suggest that this unilateral response in theL. pennellii×L. esculentum cross is more accurately referred to as "unilateral incongruity” (UI) rather than interspecific incompatibility. Periclinal chimeras were used to determine the tissues involved in UI. The results of crosses with the available chimeras indicate that the female parent must beL. pennellii at either LI (layer 1) or both LI and LII (layer 2) and the male parent must beL. esculentum at either LII or both LI and LII to observe UI similar to that seen in theL. pennellii×L. esculentum cross. Pollinations with a mixture of pollen fromL. pennellii and from transgenicL. esculentum plants harboring a pollen-specific GUS reporter gene marker were used to ascertain whether the growth of the pollen tubes of either species was modified as a possible means of overcoming UI. We found no evidence of communication between the two types of pollen tubes to either enhance or restrict all pollen tube growth. Springer-Verlag, 1996 Tomato nationallicence Interspecific hybridization nationallicence Incongruity nationallicence Self incompatibility nationallicence Reproductive barriers nationallicence Liedl B. Department of Plant Breeding, Cornell University, 252 Emerson, 4853-1901, Ithaca, NY, USA aut McCormick S. Plant Gene Expression Center, USDA/ARS-University of California-Berkeley, 800 Buchanan Street, 94710, Albany, CA, USA aut Mutschler M. Department of Plant Breeding, Cornell University, 252 Emerson, 4853-1901, Ithaca, NY, USA aut Sexual Plant Reproduction Springer-Verlag 9/5(1996-09-01), 299-308 0934-0882 9:5<299 1996 9 497 https://doi.org/10.1007/BF02152705 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02152705 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Liedl B. Department of Plant Breeding, Cornell University, 252 Emerson, 4853-1901, Ithaca, NY, USA aut NATIONALLICENCE 700 1- McCormick S. Plant Gene Expression Center, USDA/ARS-University of California-Berkeley, 800 Buchanan Street, 94710, Albany, CA, USA aut NATIONALLICENCE 700 1- Mutschler M. Department of Plant Breeding, Cornell University, 252 Emerson, 4853-1901, Ithaca, NY, USA aut NATIONALLICENCE 773 0- Sexual Plant Reproduction Springer-Verlag 9/5(1996-09-01), 299-308 0934-0882 9:5<299 1996 9 497 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer