Breaking breeding barriers in Lycopersicon. 2. Breakdown of self-incompatibility in L. peruvianum (L.) Mill.

Abstract

Attempts were made to break the self-incompatibility in L. peruvianum by selection of mutated S-alleles through large-scale self-pollination on clones with pollen which was mutagenically treated in different stages of development . Besides self-compatibility was searched for in inbred lines .The self-incompatibility in L. peruvianum was found to be very strict indeed . From more than 22,000 self-pollinations on 5 clones 1527 seeds were obtained, seed set being very erratic . The possible causes of this seed set are discussed . From 1527 seeds 1036 plants were raised and tested for self-compatibility .In the progenies of 4 clones from 823 plants tested, 7 were more or less self-compatible . It is concluded that this self-compatibility was spontaneous and not the result of the mutagenic treatment .In the progeny of the fifth clone plants were found which reacted as self-compatible at a temperature of about 40°C and as self-incompatible at lower temperatures . It is suggested that this character -a high temperature sensitive incompatibility reactionis governed by one recessive gene .In inbred lines plants were found with a stable form of self-compatibility and also plants with a high temperature sensitive incompatibility reaction.The problems of an incompatibility research on inbred material are discussed . A brief survey is given of some of the characters found in inbred L . peruvianum .

Effect of inbreeding on autogamy in Phlox

“…Thus the Phlox response is not unexpected. In moderately self-fertile plants, inbreeding often reduces the level of selffertility (Medicago sativa, Wilsie & Skory, 1948;Wilsie, 1958;Melton, 1970;Viciafaba, Drayner, 1956, 1959 Holden & Bond, 1960; Lycopersicon peruvianum, Hogenboom, 1972;Ranunculus acris, Osterbye, 1986). parent values varied from zero to 24 per cent; the mean was 9.17 per cent.…”

Genetic instability at the S-locus of Lycopersicon peruvianum plants regenerated from in vitro culture of anthers: Generation of new S-specificities and S-allele reversions

“…Extensive studies with radiations and chemical mutagens have shown that none generated new S-alleles (Lewis, 1949(Lewis, , 1951Lewis and Crowe 1954;Pandey, 1956Pandey, , 1965Brewbaker and Natarajan 1960;de Nettancourt and Ecochard, 1968;Hoffman, 1971;de Nettancourt, 1974, 1975), thus suggesting that new 5-specificities probably do not result from point mutations t the S-locus (see Sree Ramulu, 1980). Inbreeding, the only method which so far has generated new S-alleles ldads to some processes which result under favourable conditions in the generation of new 5-specificities (Denward, 1963;de Nettancourt and Ecochard, 1969;de Nettancourt et a!., 1971;Pandey, 1970aPandey, , 1972Pandey, , 1977Hogenboom, 1972;Anderson et al, 1974;Sree Ramulu, 1982). The S-alleles are stable under the conditions of a relatively high degree of heterozygosity and the S-allele dependent polygenic system is presumably drastically modified by inbreeding.…”

Breaking breeding barriers in Lycopersicon. 3. Inheritance of self-compatibility in L. peruvianum (L.) Mill.

“…Segregations were tested with the aid of binomial probability paper . Material and methods not described here were described earlier (HOGENOOM, 1972) .…”

“…In this paper an attempt will be made to determine the genetics of the self-compatibility which was found in Lycopersicon peruvianum (HOGENOOM, 1968(HOGENOOM, , 1972 . This study is necessary to come to an efficient use of the self-compatibility in pre-breeding of L .…”