Influence of Zinnia angustifolia HBK genotype on embryonic and vegetative development of Z. angustifolia x Z. elegans Jacq. interspecific hybrids

1987 ◽  
Vol 73 (5) ◽  
pp. 716-723 ◽  
Author(s):  
T. H. Boyle ◽  
D. P. Stimart ◽  
G. R. Bauchan
Keyword(s):  
Interspecific Hybrids ◽  
Vegetative Development ◽  
Zinnia Angustifolia

Cytology and breeding behavior of interspecific hybrids and induced amphiploids of Zinnia elegans and Zinnia angustifolia

1984 ◽  
Vol 26 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Veronica M. Terry-Lewandowski ◽  
Gary R. Bauchan ◽  
Dennis P. Stimart
Keyword(s):  
Disease Resistance ◽  
Interspecific Hybrids ◽  
Colchicine Treatment ◽  
Zinnia Elegans ◽  
Breeding Behavior ◽  
Contributing Factors ◽  
Zinnia Angustifolia ◽  
Partial Homology ◽  
Partial Fertility ◽  
Homoeologous Chromosomes

Cytological studies were performed on interspecific hybrids and induced amphiploids of Zinnia angustifolia HBK (2n = 22) and Zinnia elegans Jacq. (2n = 24) to ascertain their potential in serving as intermediaries in the transfer of genes for disease resistance. Partial fertility was restored in sterile F1 hybrids (2n = 23) through colchicine treatment of axillary buds. Lagging univalents and irregular distribution of chromosomes to the gametes were the major contributing factors to the sterility observed among the F1 hybrids. Bivalent associations in the F1 indicated partial homology between parental genomes. The induced amphiploids (2n = 46) formed predominantly bivalents at metaphase I owing to the suppression of pairing between homoeologous chromosomes. Consequently, these segmental allopolyploids resembled diploids in their cytological and genetic behavior and bred true to their intermediate condition with little or no segregation in later generations. It is postulated that the gene(s) controlling chromosome pairing is derived from Z. elegans. The cytological and genetic performance of colchicine-induced amphiploids of Z. elegans and Z. angustifolia suggest considerable potential for the improvement of Z. elegans cultivars with respect to disease resistance and the immediate stabilization of characters through genetic uniformity.

scholarly journals PATHWAYS OF BACKCROSSING ZINNIA ANGUSTIFOLIA × Z. ELEGANS INTERSPECIFIC HYBRIDS TO THE PARENTAL SPECIES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1070a-1070
Author(s):  
Thomas H. Boyle
Keyword(s):  
Powdery Mildew ◽  
Pollen Tube ◽  
Pollen Germination ◽  
Interspecific Hybrids ◽  
Xanthomonas Campestris ◽  
Parental Species ◽  
Developmental Abnormalities ◽  
Erysiphe Cichoracearum ◽  
Zinnia Angustifolia ◽  
Pollen Tube Penetration

Allotetraploid Z. angustifolia × Z. elegans hybrids (2 n =46) were reciprocally backcrossed to Z. angustifolia (2 n = 22 or 44) and Z. elegans (2 n = 24 or 48). Pollen germination and pollen tube penetration of the stigmatic surface were observed for all 8 cross combinations. At 14 days after pollination, the percentage of florets with embryos ranged from 0 to 69%, and some hybrid embryos exhibited developmental abnormalities. Seed-propagated backcross (BC1) populations were generated with Z. angustifolia (2 n =44)as ♀ or ♂, and Z. elegans (2 n =48) as ♀ BC1 progeny from these 3 crosses demonstrated low to high levels of resistance to bacterial leaf and flower spot (incited by Xanthomonas campestris pv. zinniae) and high levels of resistance to powdery mildew (incited by Erysiphe cichoracearum). BC1 hybrids derived from crossing allotetraploid hybrids as ♀ and Z. elegans (2 n =48) lines have commercial potential as disease-resistant, flowering annuals.

Bed behavioral assessment of tomato varieties in Cote d Ivoire

2015 ◽  
Vol 5 (1) ◽  
pp. 513-522
Author(s):  
Jean-Claude N'ZI ◽  
Lassina FONDIO ◽  
Mako Francois De Paul N’GBESSO ◽  
Andé Hortense DJIDJI ◽  
Christophe KOUAME
Keyword(s):  
Behavioral Assessment ◽  
Development Stage ◽  
Research Centre ◽  
Vegetative Development ◽  
Potential Yield ◽  
Tomato Plants ◽  
Bacterial Diseases ◽  
Damage Rate ◽  
Fruit Damage ◽  
Tomato Breeding

Thirty accessions of tomato including twenty eight introduced accessions from The World Vegetable Center-AVRDC and as controls, two commercial varieties Mongal and Calinago, were assessed for agronomic performances at the Experimentation and Production Station of Angud dou of the National Agronomic Research Centre (CNRA) located in the South of Cote d Ivoire. The trial was arranged in a randomized block with three replications. The following parameters were determined at vegetative development stage: plant height at flowering stage, susceptibility of accessions to diseases, day to 50% flowering and day of first harvest, production duration, fruit length, fruit diameter, total number of fruits, number of fruits per plant, potential yield, net yield and fruit damage rate. Results showed that the commercial variety Mongal, with a potential yield of 15.9 and a net yield of 13.1 t ha-1, was the most productive. All the introduced accessions from AVRDC recorded the lowest potential yields from 2.2 to 9.7 t ha-1, and net yields from 1.7 to 8.6 t ha-1. In addition, accessions WVCT8, FMTT847 and WVCT13 were severely infested by bacterial wilt. The reduction of the net yield of tomato accessions resulted in the high fruit damage rates. For the future tomato breeding work, it would be appropriate to introduce into the trials bacterial diseases tolerant varieties. Moreover, some studies could be undertaken to determine the nature of the bacteria involved in the plant wilting and to find out the causal agent of the tomato plants burning at the fructification stage reducing the harvest duration.

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