Associated changes in the attributes of wheat populations mass-selected for seed size

1973 ◽  
Vol 24 (2) ◽  
pp. 179
Author(s):  
GM Bhatt ◽  
NF Derera
Keyword(s):  
Seed Size ◽  
Kernel Hardness ◽  
Correlated Response ◽  
Mass Selection ◽  
Wheat Protein ◽  
Agronomic Characters ◽  
Economic Significance ◽  
Flour Protein ◽  
Protein Flour ◽  
Selection For

Evaluation of wheat populations mass-selected for seed size was made [or agronomical and quality characters in F2 and FQ generations of the crosses. Estimates of means and variances for these characters and their correlation with seed size were obtained to study the correlated response to selection for seed size. The expression of quality characters (test weight, milling extract, wheat protein, flour protein, and kernel hardness) was found to be independent of the expression of seed size in all the crosses studied. In the case of agronomic characters, however, the crosses behaved differently so far as the correlated response was concerned. It was concluded that in the crosses studied, mass selection for seed size could be practiced with certain associated advantages and without adverse response for most of the characters of economic significance in wheat.

MASS SELECTION FOR POST-WEANING GROWTH IN SWINE. V. CORRELATED RESPONSE OF REPRODUCTIVE TRAITS AND PRE-WEANING GROWTH

1976 ◽  
Vol 56 (4) ◽  
pp. 791-801
Author(s):  
I. GARNETT ◽  
G. W. RAHNEFELD
Keyword(s):  
Birth Weight ◽  
Average Daily Gain ◽  
Reproductive Traits ◽  
Correlated Response ◽  
Mass Selection ◽  
Gestation Length ◽  
Control Line ◽  
Weaning Weight ◽  
Selection For ◽  
Daily Gain

Female reproductive performance and pre-weaning survival and growth were examined in a population of swine over 11 generations of selection for post-weaning average daily gain (ADG). Three separate breeding groups were used: (1) a Lacombe (L) line selected each generation for ADG, (2) a Yorkshire control (Y) line, and (3) a crossbred Lacombe × Yorkshire group (LY) generated each generation from the L and Y lines. Breeding group differences were evident for litter size, perinatal mortality, pre-weaning mortality, gestation length, birth weight, pre-weaning average daily gain (PreADG) and weaning weight. Selection did not affect number born, number born alive, number weaned or birth weight. When the values for the L line were expressed as a deviation from the control, pre-weaning mortality showed an increase. The increase appeared to be due to a decrease in the control rather than an increase in the L line. Gestation length showed a negative response to selection. As in the case of pre-weaning mortality, the response appeared to be a reflection of the instability of the control line. Genetic gains in PreADG of 0.004 kg/day/generation were realized in both the L line and LY group. Correspondingly, responses of 0.18 and 0.19 kg/generation were realized for weaning weight in the L line and LY group.

R-nj ALEURONE COLOR SELECTION AND NITROGEN RESPONSE IN OPAQUE-2 MAIZE

1989 ◽  
Vol 69 (3) ◽  
pp. 741-747
Author(s):  
H. Z. CROSS ◽  
H. DOSSO
Keyword(s):  
Field Experiments ◽  
Agronomic Traits ◽  
Seedling Emergence ◽  
Kernel Weight ◽  
Low Fertility ◽  
Correlated Response ◽  
Mass Selection ◽  
Nitrogen Response ◽  
Color Selection ◽  
Selection For

Field experiments were conducted to determine if mass selection for degree of aleurone anthocyanin pigmentation controlled by R-nj could improve agronomic deficiencies associated with the o2 (opaque) phenotype of a maize (Zea mays L.) synthetic (NDSE). Divergent mass selection was used to develop high color (HC), low color (LC), and randomly sampled (RC) check substrains which were tested in 1982 at two low-fertility, pollen isolated sites (a clay loam, Vertic Haplaquoll with 7.2 pH and a silt loam, Aerie Calciaquoll with a 7.6 pH at Fargo and Casselton, N.D., respectively). Grain yield and agronomic traits were estimated for each of four N application rates at each site. N fertilizer increased grain yields and kernel weights. High color strains yielded highest at 136 kg ha−1 of N, outproducing RC strains. At 204 kg ha−1 of N, yield of HC strains declined and LC strains out-yielded HC strains. Low color selection significantly increased test weight, kernel weight, cob diameter, seedling emergence, and shelling ratio compared to RC strains in NDSE while HC selection increased kernel weight, cob diameter, and reduced ear moisture and protein contents compared to RC selection. Selection for LC improved several traits which were deficient in opaque-2 maize, and use of the R-nj gene may be useful in improving opaque-2 maize.Key words: Aleurone, anthocyanin, correlated response, ear moisture, mass selection, maize.

MASS SELECTION FOR POSTWEANING GROWTH IN SWINE. III. CORRELATED RESPONSE IN WEANING WEIGHT AND FEED EFFICIENCY TO RECURRENT SELECTION FOR POSTWEANING AVERAGE DAILY GAIN IN SWINE

1973 ◽  
Vol 53 (2) ◽  
pp. 173-178
Author(s):  
G. W. RAHNEFELD
Keyword(s):  
Genetic Correlation ◽  
Feed Efficiency ◽  
Average Daily Gain ◽  
Direct Selection ◽  
Correlated Response ◽  
Mass Selection ◽  
Total Response ◽  
Weaning Weight ◽  
Selection For ◽  
Daily Gain

Correlated response in weaning weight and feed efficiency were estimated for a genetically variable population of swine selected during nine generations for postweaning average daily gain. Total response in weaning weight to direct selection for gain was 0.03 kg per generation. This was 3.1% of the predicted response. The estimate of genetic correlation between postweaning average daily gain and weaning weight was found high and positive (> 1). Total response in feed efficiency to direct selection for gain was −0.58 kg per generation. This was 10% of the predicted response. The estimate of genetic correlation between postweaning gain and feed efficiency was −0.35.

Twenty Cycles of Divergent Mass Selection for Seed Size in Corn 1

Crop Science ◽  
1987 ◽  
Vol 27 (6) ◽  
pp. 1113-1116 ◽  
Author(s):  
M. O. Odhiambo ◽  
W. A. Compton
Keyword(s):  
Seed Size ◽  
Mass Selection ◽  
Selection For

MASS SELECTION FOR POSTWEANING GROWTH IN SWINE. VI. MEANS, HERITABILITIES, GENETIC AND PHENOTYPIC CORRELATIONS, AND CORRELATED RESPONSE OF CARCASS TRAITS

1983 ◽  
Vol 63 (1) ◽  
pp. 49-58 ◽  
Author(s):  
G. W. RAHNEFELD ◽  
R. L. CLIPLEF ◽  
I. GARNETT ◽  
R. M. McKAY
Keyword(s):  
Average Daily Gain ◽  
Carcass Traits ◽  
Correlated Response ◽  
Mass Selection ◽  
Correlated Responses ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Selection For ◽  
Color Score ◽  
Daily Gain

Means, heritabilities, genetic and phenotypic correlations, and correlated responses in carcass traits (total carcass backfat, carcass length, area 1. dorsi, ham weight, percentage ham of side, percentage lean in ham face, color score, texture score, and marbling score) during 11 generations of selection for postweaning average daily gain were studied on a selected Lacombe line, a Yorkshire control line, and a crossbred Lacombe × Yorkshire group generated each year from the two lines. With the exception of color score, the heritability estimates were moderate to high. Genetic and phenotypic correlations between average daily gain and the carcass traits ranged from − 0.16 to 0.46 and from − 0.07 to 0.15, respectively. Correlated responses in the carcass traits were very small. Key words: Swine, carcass traits, selection, heritabilities, correlations

Correlated response to selection for litter size in pigs: II. Carcass, meat, and fat quality traits

2002 ◽  
Vol 80 (10) ◽  
pp. 2566 ◽  
Author(s):  
J. Estany ◽  
D. Villalba ◽  
M. Tor ◽  
D. Cubiló ◽  
J. L. Noguera
Keyword(s):  
Litter Size ◽  
Correlated Response ◽  
Quality Traits ◽  
Response To Selection ◽  
Fat Quality ◽  
Selection For
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