Heritability Of Quality Traits Research Articles

Multivariate estimate of heritability for quality traits in tomatoes by the multiple factor analysis

Abstract: The objective of this work was to evaluate a multiple factor analysis approach to estimate heritability for quality traits in tomatoes (Solanum lycopersicum), taking as a reference the values of heritability obtained through the classical method offspring-parent regression. A total of 18 F3 tomato families originated from the selfing of 18 individuals from a second-cycle hybrid were evaluated. In both generations, ten quantitative traits related to fruit quality were assessed. The multiple factor analysis showed that some of the evaluated traits performed differently and others similarly between generations. Heritability is low or null for some traits, such as shelf life and reflectance percentage, and high for others, as weight and shape. That analysis also enables the study of the global connection between both generations through the RV (F3, F2) coefficient, which measures the correlation between two matrix configurations. RV was 0.503 and may be associated with the general heritability of all data. The multiple factor analysis is a valid multivariate technique to evaluate heritability for quality traits in tomatoes.

Genetic variation of loin and ham quality in Finnish Landrace and Large White pigs

Selection potential for meat quality of economically important loin (longissimus) and ham muscles (adductor, semimembranosus, biceps femoris) has been assessed. Ultimate pH (pHu), meat colour (lightness, redness and yellowness), drip loss and two visually scored colour traits were recorded from 483 Finnish Landrace and 494 Finnish Large White station test pigs in a half-sib design. A univariate restricted maximum likelihood procedure was used to estimate variance components. The statistical model contained age at beginning of test, sex and time lapse from slaughter to dissection as fixed effects and slaughter batch, common environment of littermates and additive genetic effect of the animal as random effects. The average pHu values in adductor and semispinalis were between 5.6 and 6.1. The pHu were on average 5.4 and 5.5 in longissimus and semimembranosus respectively, with the latter two being lower than optimum values of 5.6 to 5.9. Lightness for semimembranosus turned to be clearly lighter (62) than for other muscles. Lightness for longissimus (56) was slightly lighter than optimum (from 48 to 54). The heritability varied from zero to 0.45 for pHu, from 0.02 to 0.34 for lightness, from 0.17 to 0.56 for redness, from zero to 0.28 for yellowness and from 0.05 to 0.16 for drip loss. Heritability for redness values was considerably higher than heritability for other meat quality traits. The heritability of quality traits spoke for possibilities for genetic improvement of meat quality. Genetic correlations between quality traits (pHu and lightness) and average daily gain varied strongly among breeds and muscles. Genetic correlations between meat-% and pHu were in most cases high and unfavourable (rg from –0.36 to –0.68 except in longissimus, where it was 0.11). Genetic correlations between meat-% and lightness were unfavourable in Finnish Large White (from 0.47 to 0.92) but in Finnish Landrace estimates varied among muscles (from –0.40 to 0.47). Due to these results, the ham quality (pHu and lightness for semimembranosus) was included in the selection criteria for pork quality in the Finnish pig improvement programme.;

Genetics of Postharvest Longevity and Quality Traits in Late Generation Crosses of Antirrhinum majus L.

Progeny of 158 F5 × F5 crosses of Antirrhinum majus (snapdragon) selected within and among cut flower postharvest longevity (PHL) categories (long = 12.6-16.8 days, middle = 9.3-12.1 days, and short = 4.8-8.9 days) were evaluated for PHL and quality traits. Results were compared with previous studies involving F2 × F2 progeny, and F3, F4, and F5 inbred lines. Heritability of PHL in F5 × F5 progeny (0.77 ± 0.11) agrees with that of inbred lines (0.79 to 0.81) but is higher than in F2 × F2 progeny (0.41). Therefore, selection for increased PHL should progress more rapidly and predictably through application of inbred lines rather than F2 individuals. Significant differences between F5 × F5 progeny PHL categories confirm PHL is heritable with a significant additive component. Heritabilities of quality traits in A. majus are high, suggesting selection for quality traits should progress without difficulty. Phenotypic and genotypic correlations of PHL with quality traits are not consistently significant across PHL studies in A. majus. Discrepancies between studies suggest most traits may not be correlated to PHL or are subject to strong environmental influence.

Genetic variability of meat quality traits in Chianina beef cattle

The heritability of quality traits (chemical composition, colour, tenderness and water-holding capacity) of the meat deriving from three muscles (Triceps brachii, Longissimus dorsi and Semitendinosus) was evaluated in 92 young Chianina bulls. The animals were raised on two farms with different feeding programs, and were slaughtered at approximately 19 months of age. Single pair correlations were considered in order to evidence the relationships between the same traits detected in the three muscles and between all the traits of the same muscle.The h2 values range from 0.00 to 0.24 for the chemical composition, from 0.00 to 0.19 for colour parameters, from 0.03 to 0.31 for those observed after 48 h, and from 0.00 to 0.08 for tenderness and water-holding capacity. The values were not homogeneous for the three muscles. The most heritable trait was yellowness (b*48) in all three muscles, with values of 0.11 in the Longissimus dorsi, 0.23 in the Semitendinosus, and 0.31 in the Triceps brachii. Conversely, tenderness appeared to have a low heritability, as did the parameters relating to the water-holding capacity. Colour traits observed before and after 48 h of storage generally were significantly and positively correlated, indicating that certain colour characteristics are maintained even after 48 h of storage. There was not always a close relationship between the traits of each muscles: significant correlations existed between the Triceps brachii and the Longissimus dorsi muscles, confirming the similar quality traits of their meat, while there were considerable differences between these muscles and the Semitendinosus.

HERITABILITIES OF AND CORRELATIONS AMONG QUALITY TRAITS IN WHEAT

Quality data from Western Canadian Cooperative Wheat Tests were analyzed. Standard deviations of 25 different quality measurements were determined and will allow wheat breeders to assess the significance of differences in their material. Estimates of heritability indicated that protein content and remix loaf volumes were highly heritable while gassing power, diastatic activity and other measures of amylase activity appeared to be influenced mainly by environmental factors. It was recognized that estimates of heritability were probably biased upward due to the nature of the data, and a need for studies designed for the purpose of estimating heritability of quality traits was expressed. Correlations among quality measurements were estimated. Prediction of loaf volumes on the basis of measurements on flour were quite successful, and indicated the importance of measurements such as protein content, farinograph development time and gassing power in early generation selection for quality.