Pollen fertility in Java × New Guinea Impatiens interspecific hybrids

Abstract

Viable pollen-producing hybrids were obtained from the crosses New Guinea Impatiens Plant Introductions (P.I.'s) (2n = 32) × Java Impatiens P.I. 349629(2n = 16). The hybrids were crossed with a 24-chromosome amphidiploid ‘Tangeglow,’ resulting in 2n = 34-chromosome hybrids. One of these 34-chromosome hybrids was crossed with P.I. 349692 (2n = 16), producing two offspring having chromosome counts of 2n = 24 and 2n = 30. Subsequent crosses using the 30-chromosome hybrid showed a continuing tendency for production of viable partly unreduced gametes.

Formation of Unreduced Pollen by an Impatiens Hawkeri × Platypetala Interspecific Hybrid

“…Root-tip cells of the other 4 seedlings from the Tangeglow x 7851-1 cross also showed only 4 I. aurantiaca chromosomes (data not shown). Since Tangeglow is known to contain a full 2n complement of 8 large I. aurantiaca chromosomes in somatic cells (PASUTTI and WEIGLE 1980), Tangeglow could not have contributed an unreduced egg, because 6G157-7 and its sibs did not contain 8 I. aurantiaca chromo- Fig. 2a and b. Microspores from dyads and tetrads of 7851-1. a Microspores from 5 mm long flower buds.…”

“…Interspecific crosses amongst these 3 species have been successful, even though ploidy and chromosome size is different in each case, with I. hawkeri (2n = 32), I. platypetala (2n = 16), and I. auranriuca (2n = 8) forming an apparent polyploid series, with I. aurantiuca having larger chromosomes than I. huwkeri or I. plutypetala (PASUTTI and WEIGLE 1980). In a study of the cytogeography of Impatiens L., JONES and SMITH (1966) concluded that in New Guinea and adjacent islands, the basic chromosome number was x = 8 .…”

“…In spite of the different ploidies amongst these species and the corresponding sterility barriers, some interspecific hybrids have been found pollen fertile (PASUTTI et al 1977;PASUTTI and WEIGLE 1980;HICKS et al 1987;STEPHENS et al 1988). One hybrid seedling in particular, I .…”

In vitro pollen germination and viability of a Java × New Guinea Impatiens interspecific hybrid

“…Interspecific hybrids obtained from crosses among New Guinea (2n = 32), Java (2n = 16), or Celebes (2n = 8) Impatiens are often sterile (2,3,7,8,9). Male sterility has impeded the development of hybrids with a combination of desirable characteristics from several species (8).…”

“…Male sterility has impeded the development of hybrids with a combination of desirable characteristics from several species (8). Methods for achieving fertility have been pursued with some success ( 1 , 2 , 4, 7 , 8, 9).…”