scholarly journals Parent selection for cocoa resistance to witches'-broom

2010 ◽  
Vol 45 (7) ◽  
pp. 680-685 ◽  
Author(s):  
Stela Dalva Vieira Midlej Silva ◽  
Edna Dora Martins Newman Luz ◽  
José Luis Pires ◽  
Milton Macoto Yamada ◽  
Lindolfo Pereira dos Santos Filho
Keyword(s):  
North Carolina ◽  
Combining Ability ◽  
Recurrent Selection ◽  
General Combining Ability ◽  
Moniliophthora Perniciosa ◽  
Disease Symptoms ◽  
The North ◽  
Parent Selection ◽  
Selection For ◽  
Different Origins

The objective of this work was to identify genotypes with high general combining ability for resistance to witches'-broom (Moniliophthora perniciosa) in populations formed from a first cycle of recurrent selection. Highly productive and resistant clones from different origins were interbred using the North Carolina II design. The clones SCA 6, CSUL 7, RB 39, CEPEC 89, OC 67, BE 4, EEG 29 and ICS 98 were used as paternal parents, while the maternal ones were NA 33, CCN 10, IMC 67, P 4B, CCN 51, CEPEC 86, SGU 54 and ICS 9. Twenty days after germination, 56 seedlings of each cross (four replicates of 14 seedlings) received the inoculation of a 1-mL suspension with 7.5x10(4 ) basidiospores mL-1. Symptoms were evaluated 60 days after inoculation. Significant differences were observed among paternal and among maternal parents, for resistance to witches'-broom assessed according to the proportion of progeny seedlings with the disease symptoms. Differences were also observed between groups of mothers or fathers previously defined as resistant, and groups previously defined as susceptible. It is possible to obtain a combination of genes that can increase the level of resistance to witches'-broom directly from the first cycle of recurrent selection.

scholarly journals Diallelic analysis for lysine and oil contents in maize grains

2009 ◽  
Vol 66 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Leonardo Oliveira Medici ◽  
Salete Aparecida Gaziola ◽  
Vanderlei Aparecido Varisi ◽  
José Antonio Carmezini de Paula ◽  
Renato Rodrigues Ferreira ◽  
...  
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Oil Content ◽  
General Combining Ability ◽  
Lysine Content ◽  
Nitrogen Levels ◽  
N Level ◽  
Complete Series ◽  
Selection For ◽  
Selection Of

Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA or SCA for oil content, however a positive correlation was observed between lysine and oil contents in the hybrids, in the lines and even in the control cultivars. The results indicate the effectiveness of selection for lysine content, irrespective of N level, in the studied non-opaque maize lines, and the possibility of achieving both high lysine and oil content in grains.

A Model for Selecting Viticultural Sites in the Piedmont Triad Region of North Carolina

2016 ◽  
Vol 7 (3) ◽  
pp. 38-70 ◽  
Author(s):  
John Walter Nowlin ◽  
Rick L. Bunch
Keyword(s):  
North Carolina ◽  
Wine Industry ◽  
Land Use Land Cover ◽  
Site Suitability ◽  
The North ◽  
Area Of Interest ◽  
Fast Pace ◽  
North Carolina Piedmont ◽  
Selection For ◽  
A Site

The North Carolina wine industry is growing at a fast pace. Many new vineyards are being planted with European varieties. Vitis vinifera varieties in general are the most challenging species of grape grown, requiring considerable effort to consistently produce yields of appropriate volume and good quality. The model produced in this research was designed to help guide site selection for V. vinifera vineyards in the North Carolina Piedmont. This is accomplished using a site suitability model and predictive geophysical parameters. The area of interest is Rockingham County, North Carolina. The model consists of four sets of factors each weighted and combined into sub-model composites. These sub-model composites represent the capability/suitability of: topography, soil, land use/land cover, and climate. The four sub-model composites were weighted and combined to produce the final output that summarizes the viticultural site suitability for the study area.

Thrips (Thysanoptera: Thripidae) Tolerance in Cotton: Sources and Heritability

1997 ◽  
Vol 32 (4) ◽  
pp. 460-471 ◽  
Author(s):  
Daryl T. Bowman ◽  
Jack C. McCarty
Keyword(s):  
North Carolina ◽  
Gossypium Hirsutum ◽  
Combining Ability ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
General Combining Ability ◽  
Sources Of Resistance ◽  
Gossypium Hirsutum L ◽  
F2 Generation ◽  
F1 Generation

Thrips (Thysanoptera: Thripidae) resistance or tolerance in cotton, Gossypium hirsutum L., is often associated with extreme pubescence. This is undesirable because hairy (pubescent) plants tend to have more trash in harvested lint which reduces the price received by growers. Two other possible sources of resistance include gossypol and thick lower epidermal cells, the latter has been found in G. barbadense L. Five G. barbadense genotypes were mated in a North Carolina Design II to 4 upland cultivars to evaluate combining ability. In addition, 90 converted racestocks were screened for tolerance to thrips. Experiments were designed to evaluate tolerance or resistance by comparing plots with and without thrips. Two G. barbadense parents had tolerance to thrips while two upland cultivars also exhibited tolerance. In the F1 generation, general combining ability was significant for thrips damage ratings among the G. barbadense parents. In the F2 generation, all characters exhibited specific combining ability. Thus, non-additive genetic variance predominates measures of thrips tolerance.

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