Chromosome association and pollen fertility in some interspecific hybrids of Lilium

Euphytica ◽  
1982 ◽  
Vol 31 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Yoshito Asano
Keyword(s):  
Pollen Fertility ◽  
Interspecific Hybrids ◽  
Chromosome Association

scholarly journals Meiotic analysis in induced tetraploids of Brachiaria decumbens Stapf

2011 ◽  
Vol 11 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Carine Simioni ◽  
Cacilda Borges do Valle
Keyword(s):  
Chromosome Segregation ◽  
Pollen Fertility ◽  
Interspecific Hybrids ◽  
Somatic Chromosome ◽  
Breeding Program ◽  
Meiotic Behavior ◽  
Brachiaria Decumbens ◽  
Meiotic Analysis ◽  
Chromosome Duplication

The meiotic behavior of three tetraploid plants (2n=4x=36) originated from somatic chromosome duplication of sexually reproducing diploid plants of Brachiaria decumbens was evaluated. All the analyzed plants presented abnormalities related to polyploidy, such as irregular chromosome segregation, leading to precocious chromosome migration to the poles and micronuclei during both meiotic divisions. However, the abnormalities observed did not compromise the meiotic products which were characterized by regular tetrads and satisfactory pollen fertility varying from 61.36 to 64.86%. Chromosomes paired mostly as bivalents in diakinesis but univalents to tetravalents were also observed. These studies contributed to the choice of compatible fertile sexual genitors to be crossed to natural tetraploid apomicts in the B. decumbens by identifying abnormalities and verifying pollen fertility. Intraespecific crosses should reduce sterility in the hybrids produced in the breeding program of Brachiaria, a problem observed with the interspecific hybrids produced so far.

TRISOMIC PROGENY FROM INTERSPECIFIC HYBRIDS BETWEEN HELIANTHUS MAXIMILIANI AND H. ANNUUS

1982 ◽  
Vol 24 (4) ◽  
pp. 375-384 ◽  
Author(s):  
Ernest D. P. Whelan
Keyword(s):  
High Frequency ◽  
Pollen Fertility ◽  
Interspecific Hybrids ◽  
Extra Chromosome ◽  
Chromosome Elimination ◽  
Perennial Species ◽  
Two Generations ◽  
Pollen Shed

Interspecific hybrids between the diploid (2n = 34) perennial species Helianthus maximiliani Schrad. and wild H. annuus L. (2n = 34) had multivalents in meiosis. Consecutive backcrossing of the hybrids by the open-pollinated sunflower (H. annuus L.) cv. 'Saturn' resulted in rapid normalization of meiosis. However, some plants with highly modified anthers occurred and such plants were found to be diploid, whereas many plants with normal anthers and pollen shed were trisomic (2n + 1). Trisomics were first observed in two of three progenies after two crosses by 'Saturn'. Further backcrossing of trisomic females for two generations indicated about 50% megagametophyte transmission of the extra chromosome in one line and 10% in two others. Plants with a high frequency of 17 bivalents and a univalent in diplotene-MI had a higher frequency of chromosome elimination in subsequent division stages and a lower frequency of megagametophyte transmission of the extra chromosome, compared to plants having a high frequency of 16 bivalents and a trivalent. Elimination of the extra chromosome was correlated with increased pollen fertility. Primary interchange or tertiary trisomics were implicated by meiotic and fertility observations but were not identified as to type.

Chromosome numbers, pollen fertility, and pollen size in Haworthia species and hybrids

1973 ◽  
Vol 51 (10) ◽  
pp. 1753-1759 ◽  
Author(s):  
S. K. Majumdar ◽  
H. P. Riley
Keyword(s):  
Chromosome Numbers ◽  
Pollen Fertility ◽  
Interspecific Hybrids ◽  
Diploid Species ◽  
Pollen Sterility ◽  
Statistical Analyses ◽  
Pollen Size ◽  
Tetraploid Level

Sporophytic chromosome numbers were determined for 216 species, varieties, or hybrids of the genus Haworthia. There were 152 diploids (2n = 14), 10 triploids, 38 tetraploids, 7 pentaploids, 7 hexaploids, and 2 aneuploids. Among the species studied, most of the diploids were highly fertile. The tetraploids were somewhat less so, the triploids were generally less than 50% fertile, and the pentaploids and hexaploids were generally intermediate between the diploids and the triploids. The few diploid interspecific hybrids were less fertile than the diploid species. Each additional set of chromosomes increased the pollen size, and this increment was found to be significant up to the tetraploid level. Statistical analyses of comparisons between pollen size means of the hexaploids and pentaploids, and of the pentaploids and tetraploids were not significant. Pollen sterility is interesting in connection with the problem of speciation in the Aloineae, which is discussed.

Interspecific Hybrids between Tea (Camellia sinensis) and Wilson's Camellia (C. irrawadiensis) I. Morphology and Cytology of F1 Hybrids

1975 ◽  
Vol 11 (1) ◽  
pp. 13-16 ◽  
Author(s):  
H. P. Bezbaruah
Keyword(s):  
Camellia Sinensis ◽  
Pollen Fertility ◽  
Interspecific Hybrids ◽  
Female Parent ◽  
F1 Hybrids ◽  
High Pollen ◽  
Reciprocal Crosses ◽  
Close Relationship ◽  
Anatomical Characters ◽  
Regular Meiosis

SUMMARYCrosses were made between tea (Camellia sinensis L.) and Wilson's camellia (C. irrawadiensis Barua), using tea as the female parent, but reciprocal crosses were not successful. The F1 hybrids were intermediate in morphological and anatomical characters between the parents. Regular meiosis and high pollen fertility in the hybrids clearly indicate a close relationship between the parental genomes.

Pollen fertility in Java × New Guinea Impatiens interspecific hybrids

1980 ◽  
Vol 58 (3) ◽  
pp. 384-387 ◽  
Author(s):  
David W. Pasutti ◽  
Jack L. Weigle
Keyword(s):  
Pollen Fertility ◽  
Interspecific Hybrids ◽  
New Guinea ◽  
Unreduced Gametes ◽  
Chromosome Counts ◽  
Viable Pollen ◽  
Plant Introductions ◽  
New Guinea Impatiens

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.

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