Inheritance of Low-temperature-induced Cold Acclimation Response in Blueberry

Mode of inheritance of cold hardiness (CH) in woody perennials is not wellunderstood. This study was undertaken to determine the mode of inheritance and gene action of CH in blueberry (Vaccinium section Cyanococcus). Two testcross populations (segregating for CH) derived from interspecific hybrids of V. darrowi (drw) × V. caesariense (csr) were used. Plants were cold-acclimated by a 4-week exposure to 4°C. Bud CH (LT50) was defined as the temperature causing 50% injury (visual) when subjected to controlled freeze–thaw. Results show that the drw and csr parents had an LT50 of –13° and –20°C, respectively. The F1 population exhibited mean LT50 of –14.7°C. The csr and drw testcross populations had a mean LT50 of –18° (39 individuals) and –14°C (33 individuals), respectively. Individuals of each population were distributed between parental values with center of distribution skewed toward the testcross parent. Since individuals having LT50s as same as the recurrent parents were present in each population of only 33–39 plants, data suggest that CH is determined by relatively few genes. To determine gene action, the estimates for various genetic parameters (calculated from joint scaling test) were used in generation means analysis to test various models. Results indicate that CH in blueberry can be best explained by simple-additive dominance model, whereas models including epistatic components did not satisfactorily explain the data.

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Inheritance of Resistance to Anthracnose Caused by Colletotrichum coccodes in Tomato

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.123.5.832 ◽

1998 ◽

Vol 123 (5) ◽

pp. 832-836 ◽

Cited By ~ 2

Author(s):

John R. Stommel ◽

Kathleen G. Haynes

Keyword(s):

Gene Action ◽

Colletotrichum Coccodes ◽

Inheritance Of Resistance ◽

Dominance Model ◽

Narrow Sense Heritability ◽

Breeding Lines ◽

Anthracnose Resistance ◽

Generation Means ◽

Generation Means Analysis ◽

Backcross Populations

Inheritance of resistance to tomato anthracnose caused by Colletotrichum coccodes (Wallr.) S.J. Hughes was evaluated in parental, F1, F2, and backcross populations developed from crosses between adapted resistant (88B147) and susceptible (90L24) tomato (Lycopersicon esculentum Mill.) breeding lines. Resistance was evaluated via measurement of lesion diameters in fruit collected from field-grown plants and puncture inoculated in a shaded greenhouse. Backcross and F2 populations exhibited continuous distributions suggesting multigenic control of anthracnose resistance. Anthracnose resistance was partially dominant to susceptibility. Using generation means analysis, gene action in these populations was best explained by an additive-dominance model with additive × additive epistatic effects. A broad-sense heritability (H) of 0.42 and narrow-sense heritability (h2) of 0.004 was estimated for resistance to C. coccodes. One gene or linkage group was estimated to control segregation for anthracnose resistance in the cross of 90L24 × 88B147.

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Genetics of in vitro organogenesis and precocious germination of wheat embryos

Genetics and Molecular Biology ◽

10.1590/s1415-47571998000100015 ◽

1998 ◽

Vol 21 (1) ◽

pp. 87-92 ◽

Cited By ~ 2

Author(s):

Claudia E. Lange ◽

Luiz C. Federizzi ◽

Fernando I.F. Carvalho ◽

Ana L.C. Dornelles ◽

Cristine L. Handel

Keyword(s):

Gene Action ◽

Precocious Germination ◽

Genetic Determination ◽

Wheat Embryo ◽

In Vitro Organogenesis ◽

Generation Means ◽

Generation Means Analysis ◽

Wheat Embryos ◽

Segregating Population

The genetic bases of in vitro organogenesis and precocious germination of embryos in immature wheat embryo culture were investigated using six Brazilian genotypes and their F1, F2, BC1F1 and BC2F1 generations in a generation means analysis. Four parents and one set of F1’s were also analyzed in a diallel experiment. The results indicated a complex gene action controlling both traits, with additive, dominant and epistatic effects. High broad sense heritability values were found, indicating genetic determination. Considering the complexity of gene control, genetic gain could be achieved by selecting for the traits in advanced generations of the segregating population. Low correlation values between organogenesis, precocious germination, regeneration and somatic embryogenesis (data shown in a previous report) indicated the possibility of obtaining recombinant genotypes.

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Genetic Analysis of Cut-flower Longevity in Antirrhinum majus

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.126.2.200 ◽

2001 ◽

Vol 126 (2) ◽

pp. 200-204 ◽

Cited By ~ 2

Author(s):

Kenneth R. Schroeder ◽

Dennis P. Stimart

Keyword(s):

Antirrhinum Majus ◽

Additive Effects ◽

Cut Flower ◽

Flower Longevity ◽

Dominance Model ◽

Epistatic Interactions ◽

Epistatic Model ◽

Generation Means ◽

Generation Means Analysis ◽

Postharvest Longevity

Genetics of Antirrhinum majus L. (snapdragon) cut flower postharvest longevity (PHL) was investigated by generation means analysis using a white short-lived inbred (WS) and white long-lived inbred (WL) to determine mode of inheritance and heritability. Broad and narrow sense PHL heritability was estimated at 78% and 30%, respectively. Scaling tests for adequacy of an additive-dominance model in explaining PHL inheritance suggested absence of epistasis. However, joint scaling indicated digenic or higher order epistatic interactions. Fitting of a digenic epistatic model revealed significant additive effects and nonsignificant dominance and epistatic interactions. Additionally, based on sequential model fittings all six parameters [mean, additive (a), dominance (d), a×a, d×d, and a×d] proved necessary to explain observed PHL variation. Continuous variation for PHL observed in the F2 and backcross generations suggests PHL is quantitative. Assessment of associated traits revealed a positive relationship between number of flowers opening postharvest on a cut flower and PHL. In addition, floret wilting led to short PHL while floret browning was associated with long PHL.

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Cytoplasmic effects on grain resistance to yellowberry in durum wheat

Czech Journal of Genetics and Plant Breeding ◽

10.17221/18/2010-cjgpb ◽

2010 ◽

Vol 46 (No. 4) ◽

pp. 145-148 ◽

Cited By ~ 1

Author(s):

F. Bnejdi ◽

M. Saadoun ◽

M. El Gazzah

Keyword(s):

Durum Wheat ◽

Female Parent ◽

Wheat Breeding ◽

Additive Effects ◽

Dominance Model ◽

Epistatic Model ◽

Cytoplasmic Effects ◽

Generation Means ◽

Generation Means Analysis ◽

Triticum Durum Desf

Parental, F1, reciprocal F1 (RF1), F2, reciprocal F2 (RF2), BC1P1 and BC1P2 generations of four crosses involving four cultivars of durum wheat (Triticum durum Desf.) were evaluated for grain resistance to yellowberry. Significant differences were reported for F1, F2 and their reciprocals in all crosses. A generation means analysis indicated the inadequacy of additive-dominance model and additive-dominance model considering maternal effects. However, the variation in generation means in the four crosses could be explained by a digenic epistatic model with cytoplasmic effects. Cytoplasmic effects were significant and consistent in all the crosses. Dominance effects and additive × dominance epistasis were more important than additive effects and other epistatic components. The choice of a female parent possessing grain resistance to yellowberry appeared to be decisive in durum wheat breeding for resistance to this serious seed disorder.

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Gene action for leaf conductance in three wheat crosses

Australian Journal of Agricultural Research ◽

10.1071/ar02151 ◽

2003 ◽

Vol 54 (4) ◽

pp. 381 ◽

Cited By ~ 31

Author(s):

G. J. Rebetzke ◽

A. G. Condon ◽

R. A. Richards ◽

G. D. Farquhar

Keyword(s):

Genetic Parameters ◽

Gene Action ◽

Leaf Conductance ◽

Slow Speed ◽

Generation Means ◽

Allelic Gene ◽

Large Populations ◽

Flow Through ◽

Selection For ◽

High Conductance

Selection for altered stomatal conductance has potential to improve wheat grain yields in dry and well- watered environments. Yet the slow speed with which conductance is typically measured has limited studies reporting genetic parameters for leaf conductance. A viscous air-flow porometer that measures resistance to mass flow through a leaf was used to provide rapid estimates of leaf conductance. These estimates were obtained prior to anthesis on irrigated plants representing different generations of crosses between the low conductance parent, Quarrion, and 3 high conductance varieties, Hartog, Genaro 81, and Matong. Sampling for leaf conductance was done between 08 00 and 12 00 hours under cloud-free conditions. Significant (P < 0.01) genetic differences were observed between generation means for conductance measured in different crosses and on different days. Gene action was complex with both additive and non-additive (dominance and additive-based epistasis) genetic effects important for expression of leaf conductance. There was a greater reduction in leaf conductance for Quarrion and backcross-Quarrion progeny with sampling later into the day. In turn, genetic variances for leaf conductance increased with later sampling. Family-mean heritabilities varied in size (0.06–0.70), depending on cross and time of sampling. It is suggested that breeders selecting for altered leaf conductance maximise genetic gain by delaying screening of populations until later in the day, and repeat measurements across a minimum of 2 days. Large populations of inbred families should be evaluated in order to minimise confounding through dominance and increase the probability of recovering families containing desirable non-allelic gene combinations.

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