The Genus Collinsia. Xvi. Supernumerary Chromosomes

Dhillon, T. S.; Garber, E. D.

doi:10.1002/j.1537-2197.1962.tb14924.x

“…pl. : DHILLON and GARBER 1962; o Anthoxanthum aristatum: OsTERGREN 1949; o Festuca arundinacea: BosE MARK 1957; o F estuca pratensis : BosEMARK 1957; o Phleum phleoides: BosEMARK 1957; o Alopecurus pratensis: BosEMARK 1957; o Briza media: BosEMARK 1957; o Holcus lanatus: BosEMARK 1957. The two cases of Phleurn phleoides and P. nodosum (BosEMARK 1957) deserve attention. While the first shows preferential distribution, the second does not present such a phenomenon.…”

Section: Secale Typementioning

confidence: 99%

“…(DHILLON and GARBER 1962) with one to four B's are fertile, but the occurrence of more than four B's produces total sterility.…”

Section: ) Effeci's and Genic Contentmentioning

confidence: 99%

Cytogenetics of B-Chromosomes

Battaglia

¹

1964

View full text Add to dashboard Cite

“…4), whose pollen parent had () fragments, demonstrated that at least some pollen carrying many fragments is functional. Dhillon and Garber (1962) have reported that mitotic nondisjunction of supernumerary chromosomes during formation of pollen grains in Collinsia may be responsible for the increase in the number of such chromosomes.…”

mentioning

confidence: 99%

A Cytogenetic Analysis of Certain Polyploids in Grindelia (Compositae)

Dunford

¹

1964

American Journal of Botany

View full text Add to dashboard Cite

Two diploid taxa, Grindelia procera and G. camporum, and 3 tetraploid ones, G. camporum, G. hirsutula, and G. stricta, have been studied to ascertain their interrelationships. Meiosis in diploid parental strains was regular, the common chromosome configuration being 5 rod bivalents and 1 ring bivalent. The average chiasmata frequency per chromosome was 0.60. Pollen fertility was about 90% in all strains examined. Diploid interspecific hybrids had normal meiosis with an average chiasmata frequency of 0.56 per chromosome. No heterozygosity for inversions or interchanges was detected, and pollen fertility was above 85%. Meiosis in parental tetraploid strains was characterized by the presence of quadrivalents in addition to a complementary number of bivalents. The average chiasmata frequency per chromosome was 0.59 and pollen fertility was generally about 80%. Tetraploid interspecific hybrids also had quadrivalents, normal meiosis, and high pollen fertility. Close genetic relationships between the diploids and between the tetraploids are indicated, and geographical, ecological, and seasonal barriers to gene exchange exist. Attempts to obtain hybrids between diploids and tetraploids were successful in a few cases. The hybrids were tetraploid and had normal meiosis and fertility similar to parental and F1 tetraploids. Their origin was by the union of unreduced gametes of the diploid female parent and normal pollen from the tetraploid parent. On the basis of chromosome homology, normal meiosis, plus high fertility exhibited in the diploid, tetraploid, and diploid X tetraploid interspecific hybrids, these species of Grindelia are considered to be a part of an autopolyploid complex. Gene exchange between diploids and diploids, tetraploids and tetraploids, and diploids and tetraploids is possible. Tetraploid G. camporum may have originated by hybridization between G. procera and diploid G. camporum with subsequent doubling of chromosomes and selection for the combined characteristics of the diploids.

show abstract

A Cytogenetic Analysis of Certain Polyploids in Grindelia (Compositae)

Dunford

¹

1964

American J of Botany

15

0

View full text Add to dashboard Cite

Two diploid taxa, Grindelia procera and G. camporum, and 3 tetraploid ones, G. camporum, G. hirsutula, and G. stricta, have been studied to ascertain their interrelationships. Meiosis in diploid parental strains was regular, the common chromosome configuration being 5 rod bivalents and 1 ring bivalent. The average chiasmata frequency per chromosome was 0.60. Pollen fertility was about 90% in all strains examined. Diploid interspecific hybrids had normal meiosis with an average chiasmata frequency of 0.56 per chromosome. No heterozygosity for inversions or interchanges was detected, and pollen fertility was above 85%. Meiosis in parental tetraploid strains was characterized by the presence of quadrivalents in addition to a complementary number of bivalents. The average chiasmata frequency per chromosome was 0.59 and pollen fertility was generally about 80%. Tetraploid interspecific hybrids also had quadrivalents, normal meiosis, and high pollen fertility. Close genetic relationships between the diploids and between the tetraploids are indicated, and geographical, ecological, and seasonal barriers to gene exchange exist. Attempts to obtain hybrids between diploids and tetraploids were successful in a few cases. The hybrids were tetraploid and had normal meiosis and fertility similar to parental and F1 tetraploids. Their origin was by the union of unreduced gametes of the diploid female parent and normal pollen from the tetraploid parent. On the basis of chromosome homology, normal meiosis, plus high fertility exhibited in the diploid, tetraploid, and diploid X tetraploid interspecific hybrids, these species of Grindelia are considered to be a part of an autopolyploid complex. Gene exchange between diploids and diploids, tetraploids and tetraploids, and diploids and tetraploids is possible. Tetraploid G. camporum may have originated by hybridization between G. procera and diploid G. camporum with subsequent doubling of chromosomes and selection for the combined characteristics of the diploids.

show abstract

The Genus Collinsia. Xvi. Supernumerary Chromosomes

Cited by 3 publications

References 13 publications

Cytogenetics of B-Chromosomes

Cytogenetics of B-Chromosomes

A Cytogenetic Analysis of Certain Polyploids in Grindelia (Compositae)

A Cytogenetic Analysis of Certain Polyploids in Grindelia (Compositae)

Contact Info

Product

Resources

About