scholarly journals Heterotic Patterns among Open-pollinated Sweet Corn Cultivars

1997 ◽  
Vol 122 (3) ◽  
pp. 319-324 ◽  
Author(s):  
Pedro Revilla ◽  
W.F. Tracy
Keyword(s):  
Combining Ability ◽  
Sweet Corn ◽  
Late Summer ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Planting Date ◽  
Planting Dates ◽  
Early Maturity ◽  
Late Maturity ◽  
Significant Yield

Heterotic patterns in sweet corn are weakly defined. Most sweet corn inbreds are descended from three open-pollinated cultivars: `Golden Bantam', Stowell's Evergreen', and `Country Gentleman'. Heterotic and phylogenetic relationships among these three cultivars and others are not clearly known. This investigation was designed to investigate the heterotic patterns among some historically important open-pollinated sweet corn cultivars: `Country Gentleman', `Golden Bantam', `Lindsey Meyer Blue', `Stowell's Evergreen', `Howling Mob', and `Pease Crosby'. The 15 possible hybrids from the diallel cross plus the 6 parents were grown in midspring and late summer plantings. Heterosis and combining ability effects were estimated for 13 traits. Hybrid × planting date interactions were significant for most of the main traits, hence, planting dates were analyzed separately. Average midparent heterosis for grain yield was 29.17% in the first planting date and 57.04% in the second planting. Midparent heterosis for yield and plant height were highest for hybrids with `Country Gentleman' as a parent. `Stowell's Evergreen' when crossed to `Pease Crosby', `Lindsey Meyer, and `Golden Bantam' exhibited high heterosis. The two late-maturity cultivars `Country Gentleman' and `Stowell's Evergreen' had higher general combining ability than the four early-maturity cultivars for most traits. Specific combining ability was seldom significant. Yield of `Country Gentleman' hybrids averaged over all crosses and planting dates was the highest. These data indicate a strong heterotic pattern—`Country Gentleman' × `Pease Crosby', `Golden Bantam', and `Lindsey Meyer Blue'—and a weaker one—`Stowell's Evergreen' × `Pease Crosby', `Golden Bantam', and `Lindsey Meyer Blue'.

scholarly journals Inheritance of Resistance to Goss's Wilt in Sweet Corn

1990 ◽  
Vol 115 (4) ◽  
pp. 672-674 ◽  
Author(s):  
C.L. Treat ◽  
W.F. Tracy
Keyword(s):  
Zea Mays ◽  
Combining Ability ◽  
Recurrent Selection ◽  
Sweet Corn ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Sums Of Squares ◽  
Inheritance Of Resistance ◽  
Yield Losses ◽  
Field Corn

Goss's wilt is a bacterial wilt and blight that may cause yield losses up to 50% or greater in sweet corn. Ten hybrids from a diallel cross of five sweet corn (Zea mays L.) inbreds were analyzed for resistance to Goss's wilt (Corynebacterium michiganense ssp. nebraskense Schuster, Hoff, Mandel, and Lazar) in 1987 and 1988. The inbreds used to make the diallel were widely used historically and were chosen on the basis of adaptation and relative maturity. Three hybrids were resistant and seven intermediate, while the field corn controls were extremely susceptible. General combining ability (GCA) and specific combining ability (SCA) sums of squares accounted for 94% and 6% of the variation among crosses, respectively. GCA was highly significant (P ≤ 0.01), while SCA was nonsignificant. Year differences were nonsignificant, but date of rating and hybrid × year interaction effects were significant (P 0.05). Resistance to Goss's wilt is available in sweet corn, and recurrent selection should be effective if improvement in resistance is desired.

scholarly journals Combining ability and heterosis on yield and its component traits in maize (Zea mays L.)

2016 ◽  
Vol 41 (3) ◽  
pp. 565-577 ◽  
Author(s):  
MZA Talukder ◽  
ANM S Karim ◽  
S Ahmed ◽  
M Amiruzzaman
Keyword(s):  
Combining Ability ◽  
Diallel Cross ◽  
Kernel Weight ◽  
Early Maturity ◽  
Ecological Zones ◽  
Component Traits ◽  
Additive Gene ◽  
Positive Heterosis ◽  
Half Diallel ◽  
Kernel Yield

Combining ability and heterosis were studied in a 7×7 half diallel cross in maize for grain yield and yield contributing characters. Significant general and specific combining ability variances were observed for all the characters studied. The significant estimates of GCA and SCA variances suggested the importance of both additive and non-additive gene actions for the expression studied traits. In these studies, variances due to SCA were higher than GCA for all charactesr, which revealed the predominance of non additive gene action (dominance and epistasis) for controlling these traits. Parents P1 and P4 were excellent general combiner for days to tasseling and silking while P1 and P5 for early maturity. P4 for short height and, P4 and P7 for higher thousand kernel weight. The parents P4 and P6 having good combining abilities for yield. Heterosis estimation was carried out using two commercial varieties NK40 and 900MG. When standard commercial check NK40 was used, the percent heterosis for kernel yield varied from -51.39 to 12.53%. Among the 21 F1s, 3crosses exhibited significant positive heterosis for kernel yield. The highest heterosis was exhibited by the cross P4×P6 (12.43%), P6×P7 (10.89%) and P2×P3 (9.87%) respectively. Compared with 900MG as check, the percent heterosis for kernel yield varied from -53.73 to 7.01%. Among the 21 F1s, none of the crosses exhibited significant positive heterosis for kernel yield. The highest heterosis were exhibited by the crosses P4×P6 (7.01%), P6 x P7 (5.55%) and P2×P3 (4.57%). The crosses showed significant positive SCA values could be used for variety development after verifying them across the agro-ecological zones of Bangladesh.Bangladesh J. Agril. Res. 41(3): 565-577, September 2016

HETEROSIS, COMBINING ABILITY, AND PREDICTED SYNTHETICS FROM A DIALLEL CROSS IN SUNFLOWERS (HELIANTHUS ANNUUS L.)

1966 ◽  
Vol 46 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Eric D. Putt
Keyword(s):  
Helianthus Annuus ◽  
Combining Ability ◽  
Oil Content ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Helianthus Annuus L ◽  
The Mean ◽  
Seed Characters ◽  
Mature Weight

Heterosis occurred for the eight plant and seed characters studied. It was most frequent for yield of seed and height of plant. Mean squares for general combining ability (gca) and specific combining ability (sca) were significant (P =.01) for all characters. The estimated components for gca were greater than for sca for days to mature, weight per bushel, and percent oil in the seed; less for height and yield of seed; and essentially the same for days to bloom, diameter of head, and weight per 1000 seeds.The yield of seed and percent oil in the seed, for the highest ranking 100 synthetics that could be composed from the 10 lines, was predicted in F6 assuming 50 and 60% outcrossing between F2 and F6. Virtually all values exceeded the mean performance of four check samples of commercial hybrids. Many exceeded the highest rank check for oil content in the seed. Fourteen of the highest ranking 100 synthetics for yield and 30 for oil content consisted of two or three lines. It was concluded that synthetics can be superior to the present hybrids in heterosis and that desirable synthetics can be made from only a few lines.

Selection for soyabeans with high and environmentally stable lutein concentrations

2014 ◽  
Vol 12 (S1) ◽  
pp. S12-S16 ◽  
Author(s):  
Krishna Hari Dhakal ◽  
Myoung-Gun Choung ◽  
Young-Sun Hwang ◽  
Felix B. Fritschi ◽  
J. Grover Shannon ◽  
...  
Keyword(s):  
Human Health ◽  
High Stability ◽  
Planting Dates ◽  
Early Maturity ◽  
Breeding Objective ◽  
Late Maturity ◽  
Selection For ◽  
High Concentrations ◽  
The Stability ◽  
Nutritional Benefits

Lutein has significant nutritional benefits for human health. Therefore, enhancing soybean lutein concentrations is an important breeding objective. However, selection for soybeans with high and environmentally stable lutein concentrations has been limited. The objectives of this study were to select soybeans with high seed lutein concentrations and to determine the stability of lutein concentrations across environments. A total of 314 genotypes were screened and 18 genotypes with high lutein concentrations and five genotypes with low lutein concentrations were selected for further examination. These 23 genotypes and two check varieties were evaluated under six environments (two planting dates for 2 years at one location and two planting dates for 1 year at another location). Lutein concentrations were influenced by genotype, environment and genotype × environment interactions. Genotypes with late maturity and low lutein concentrations were more stable than those with early maturity and high concentrations. Early (May) planting resulted in greater lutein concentrations than late (June) planting. Among the genotypes evaluated, PI603423B (7.7 μg/g) and PI89772 (5.8 μg/g) had the greatest mean lutein concentrations and exhibited medium and high stability across the six environments, respectively. Thus, these genotypes may be useful for breeding soybeans with high and stable seed lutein concentrations.

Planting Date Affects Survival and Height Growth of Hybrid Poplar

1986 ◽  
Vol 62 (3) ◽  
pp. 164-169 ◽  
Author(s):  
Edward A. Hansen
Keyword(s):  
Hybrid Poplar ◽  
Late Summer ◽  
Growing Season ◽  
Climatic Conditions ◽  
Planting Date ◽  
Planting Dates ◽  
Soil Frost ◽  
Growing Seasons ◽  
Poplar Cuttings ◽  
Energy Plantations

In this study I investigated the effects of planting date for soaked versus unsoaked cuttings of two hybrid poplar clones under irrigated versus unirrigated and weedy versus weed-free conditions. Cuttings were planted each year for 4 years. Survival at the end of the first growing season was generally greater than 90% for all planting dates. At the end of the second growing season survival for trees planted before July 16 was again generally more than 90%. However, cuttings planted from July 30 through August 27 showed a major decline in survival and survival of fall planted cuttings ranged from 6 to 90%. Mortality of late summer- or fall-planted cuttings occurred prior to the beginning of the second growing season and was attributed to frost heaving. The tallest trees were not those planted at the earliest possible dates (April in Rhinelander). Instead, the tallest trees at the end of the first and second growing seasons were those planted in early- and mid-May. This optimum planting period was the same regardless of clone, soaking, irrigation, or weed treatment. Actual optimum planting date would change with location and local climatic conditions. Some climatic indices may prove more universal in predicting when to plant. Although tentative, it appears that for best growth, unrooted hybrid poplar cuttings should be planted in soil warmer than 10 °C. Trees do not grow as well if planted immediately after soil frost leaves the ground. Key words: Energy plantations, plantation establishment, woody biomass, intensive culture, Populus.

COMBINING ABILITY ANALYSIS IN THE CULTIVATED STRAWBERRY

1971 ◽  
Vol 51 (5) ◽  
pp. 377-383 ◽  
Author(s):  
L. P. S. SPANGELO ◽  
R. WATKINS ◽  
C. S. HSU ◽  
S. O. FEJER
Keyword(s):  
Combining Ability ◽  
Plant Density ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Flower Stalk ◽  
Combining Abilities ◽  
Combining Ability Analysis ◽  
Strawberry Cultivars

General and specific combining abilities were analyzed for total, marketable, early, and late yield, and for flower stalk number in a diallel cross of eight strawberry cultivars. Data were recorded from individual seedlings restricted to two runner plants, thereby eliminating variability resulting from differences in plant density. General and specific combining abilities for the five characters were highly significant. Estimates of general combining ability effects taken alone were, in general, of little value in predicting the order of desirability of individual crosses.

RESPONSES TO PLANTING DATE AND POPULATION DENSITY BY EARLY-MATURING SORGHUM HYBRIDS IN ONTARIO

1981 ◽  
Vol 61 (2) ◽  
pp. 265-273
Author(s):  
D. J. HUME ◽  
YILMA KEBEDE
Keyword(s):  
Plant Density ◽  
Late Summer ◽  
Hybrid Plant ◽  
Planting Date ◽  
Planting Dates ◽  
Grain Yields ◽  
South Central ◽  
Early Maturing ◽  
Plant Densities ◽  
Sorghum Grain

Early-maturing grain sorghum (Sorghum bicolor (L.) Moench) hybrids which have potential usefulness in southern Ontario are commercially available. One such hybrid, Pride P130, and two experimental hybrids, Pride X4043 and Pride X3160, were grown at three planting dates and three plant densities in 1975 and 1976 at Elora, Ontario. There were several hybrid × planting date and hybrid × plant density interactions for the development and yield parameters measured. However, grain yields of all hybrids decreased by about 10% per week when plantings were delayed 2 or 4 wk after mid-May in 1975. In 1976, yields declined even more after late planting. Increasing populations from 75 000 to 300 000 plants/ha in 1975 increased grain yields from 4.3 to 6.0 t/ha, averaged over hybrids and planting dates. In 1976, raising populations from 150 000 to 450 000 plants/ha increased average yields from 3.2 to 3.7 t/ha. P130 was the earliest and best-yielding hybrid in both years. In 1975, which had a warm May and near-average temperatures, the best treatment yielded 7.3 t grain/ha and hybrids at all planting dates matured. The best treatment approached grain corn (Zea mays L.) yields. In 1976 with a cool spring and late summer, the highest grain yield was 5.7 t/ha with early planting, but 11 June plantings did not mature. In south-central Ontario, sorghum grain yields appear less reliable than those of corn.

GENOTYPE × ENVIRONMENT INTERACTIONS IN SMOOTH BROMEGRASS. I. YIELD

1979 ◽  
Vol 21 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Wai-Koon Tan ◽  
Geok-Yong Tan ◽  
P. D. Walton
Keyword(s):  
Genetic Variation ◽  
Analysis Of Variance ◽  
Combining Ability ◽  
Significant Variation ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Bromus Inermis ◽  
Smooth Bromegrass ◽  
Combining Ability Analysis ◽  
Half Diallel

Twenty-one progenies and the parents of a 7 × 7 half diallel cross of smooth bromegrass (Bromus inermis Leyss.) were evaluated at four locations in Alberta in each of two years, for genetic variation and genetic by environment interactions in the expression of their yield potentials. Years, locations and their interactions were highly significant in the combined analysis of variance. Combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were both important in the expression of yield, including spring, fall and annual yield, whereas GCA was more important than SCA for yield per area. Although the genotype × environment interactions were all highly significant, variation accounted for by combining ability effects was generally higher than the interaction effects of GCA and SCA respectively, with environments. High average GCA effects for spring, fall and annual yield were demonstrated for the clones UA5, UA9 and B42. These together with the high average SCA effects suggested that the three clones could be included in a synthetic to develop high yielding cultivars. The results suggested that recurrent selections involving multi-location and multi-year testing seems necessary in breeding for high yielding bromegrass cultivars in Alberta.

Inheritance of Resistance to Cercospora arachidicola and Cercosporidium personatum in Six Virginia-type Peanut Lines1,3

1980 ◽  
Vol 7 (1) ◽  
pp. 4-9 ◽  
Author(s):  
Julia L. Kornegay ◽  
M. K. Beute ◽  
J. C. Wynne
Keyword(s):  
Combining Ability ◽  
Leaf Spot ◽  
Resistance Breeding ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Leaf Spot Disease ◽  
Inheritance Of Resistance ◽  
Cercospora Arachidicola ◽  
Cercosporidium Personatum ◽  
Leaf Spots

Abstract The inheritance of resistance to two cercospora leaf-spots, Cercospora arachidicola (early leafspot) and Cercosporidium personatum (late leafspot) in Virginia-type peanuts (Arachis hypogaea L.), was determined using F1 and F2 generations and parental lines from a six parent diallel cross under natural field conditions. Two techniques for rating disease severity were employed. General combining ability, determined from both rating techniques, was significant for both F1 and F2 generations, indicating that resistance to both fungi and tolerance to infection i. e., minimal leaf defoliation, was primarily due to additive genetic effects. The six parents produced offspring with different levels of resistance to both fungi. From the estimates of general combining ability effects, only NC-GP 343 and NC 5 produced progeny resistant to both early and late leaf-spot. NC 3033 was resistant to early leafspot, but susceptible to late leafspot. NC-Ac 3139, Florigiant and NC 2 were resistant to late leafspot, but susceptible to early leaf-spot. Disease indices ranked NC 3033 and NC-GP 343 as, overall, the most resistant of the six lines and the most useful to include in a cercospora leafspots resistance breeding program.

GENERAL AND SPECIFIC COMBINING ABILITY IN SEVEN INBRED STRAWBERRY LINES

1968 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Lewis E. Aalders ◽  
Donald L. Craig
Keyword(s):  
Genetic Variation ◽  
Powdery Mildew ◽  
Combining Ability ◽  
Diallel Cross ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Additive Genetic Variation

Seedlings of a diallel cross of seven strawberry inbreds omitting reciprocals were fruited in matted rows. Per acre fruit yields were comparable with leading cultivars, but berry appearance and quality of the hybrids were poor. Differences in resistance to powdery mildew reflected the values of the cultivars from which the inbreds were derived.All four characters studied showed significant general combining ability values, and three of the four showed significant specific combining ability values. These results are consistent with previous findings of considerable amounts of non-additive genetic variation in the strawberry.

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