scholarly journals THE EFFECT OF RECURRENT SELECTION FOR REDUCTION OF PLANT AND EAR HEIGHT ON INTERNODE PATTERN IN TWO TROPICAL MAIZE (ZEA MAYS L.) POPULATIONS

1979 ◽  
Vol 59 (1) ◽  
pp. 147-150 ◽  
Author(s):  
S. C. MUCHENA ◽  
C. O. GROGAN ◽  
A. D. VIOLIC
Keyword(s):  
Zea Mays ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Tropical Maize ◽  
Family Selection ◽  
Ear Height ◽  
Selection For ◽  
Advanced Cycles

Studies were conducted to determine to what extent full-sib family selection for reduction of plant and ear height has altered the internode patterns of two tropical open-pollinated maize (Zea mays L.) populations: Tuxpeno and Mezcla Amarilla. Internode pattern diagrams were constructed by plotting successive internode lengths against order of internodes from bottom upwards. Plants in the advanced cycles of selection had both fewer and shorter internodes below the ear. This resulted in plant types that have different internode patterns compared to the original populations.

PERFORMANCE UNDER STRESS OF ADVANCED CYCLES OF FOUR POPULATIONS OF CORN (Zea mays L.) IN AN S1 PER SE RECURRENT SELECTION PROGRAM

1981 ◽  
Vol 61 (1) ◽  
pp. 29-36
Author(s):  
O. A. ADARA ◽  
L. W. KANNENBERG
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Selection Criterion ◽  
Grain Filling ◽  
Primary Selection ◽  
Per Se ◽  
Selection For ◽  
Advanced Cycles

Two cycles of S1 per se recurrent selection were conducted in four populations of corn (Zea mays L.). The primary selection criterion was a performance index: grain yield divided by percent moisture at harvest. The original (C0) source material and first cycle (C1) of selection for each population were evaluated in a favorable (1977) and an unfavorable (1978) growing season. Second cycle (C2) materials were also included in the 1978 comparisons. In 1977, C1 yielded significantly more grain than C0 in three of the four populations. In contrast, performance of C1 and C2 materials in 1978 was inferior to C0 in all populations but one. The advanced cycles of only one population showed improvement over C0 in both years. Comparisons of the 1977 data for days to silking, grain yield, and percent ear moisture at harvest suggest that rate of grain filling in C1 was higher than in C0 for all populations. The higher rates of grain filling in the advanced cycles may have caused a carbohydrate deficiency under stress (1978) so that the leaves no longer functioned normally and kernel filling was terminated prematurely. In general, the four populations showed inherent differences in their respective responses to selection, to environmental stress, and to inbreeding.

scholarly journals Molecular mapping in tropical maize (Zea mays L.) using microsatellite markers. 2. Quantitative trait loci (QTL) for grain yield, plant heigth, ear height and grain moisture

Hereditas ◽  
2004 ◽  
Vol 139 (2) ◽  
pp. 107-115 ◽  
Author(s):  
SÉRGIO TADEU SIBOV ◽  
CLÁUDIO LOPES DE SOUZA JR ◽  
ANTONIO AUGUSTO FRANCO GARCIA ◽  
ADELMO REZENDE SILVA ◽  
ALEXANDRE FRANCO GARCIA ◽  
...  
Keyword(s):  
Zea Mays ◽  
Quantitative Trait Loci ◽  
Grain Yield ◽  
Microsatellite Markers ◽  
Quantitative Trait ◽  
Zea Mays L ◽  
Molecular Mapping ◽  
Tropical Maize ◽  
Grain Moisture ◽  
Ear Height

Changes in genetic variances and heritabilities in an early white maize population following S1 selection for grain yield, Striga resistance and drought tolerance

2016 ◽  
Vol 155 (4) ◽  
pp. 629-642 ◽  
Author(s):  
B. BADU-APRAKU ◽  
M. OYEKUNLE ◽  
A. O. TALABI ◽  
B. ANNOR ◽  
I. C. AKAOGU
Keyword(s):  
Drought Tolerance ◽  
Grain Yield ◽  
Recurrent Selection ◽  
Central Africa ◽  
Maize Production ◽  
Genetic Variances ◽  
Maize Population ◽  
Ear Height ◽  
Selection For ◽  
Advanced Cycles

SUMMARYDrought is a major constraint to maize production in West and Central Africa (WCA). Assessment of genetic gain from S1 recurrent selection under drought is crucial for the development of drought tolerance breeding strategies. In an early white population, 60 S1 families each derived from the base population and three cycles of selection were evaluated under drought and well-watered conditions at two locations in Nigeria for 2 years to determine genetic variability, gains from selection and predict response to selection for grain yield and other traits. Genetic variances generally decreased for yield and other traits in advanced cycles under drought and well-watered conditions except yield and ear height under well-watered conditions. Similarly, heritabilities for yield and other traits decreased in advanced cycles under drought but increased in advanced cycles under well-watered conditions. Realized gain for yield was 0·291 t/ha, corresponding to 30·5% per cycle under drought and 0·352 kg/ha with a corresponding gain of 16·7% per cycle under well-watered conditions. Predicted gain based on C3 was 0·282 and 0·583 t/ha under drought and well-watered conditions. Low genetic variances, heritabilities and predicted gain for yield and other traits suggested a need to introgress drought tolerance genes into the population.

scholarly journals Inbreeding in two maize subpopulations selected for tassel size

2000 ◽  
Vol 57 (3) ◽  
pp. 487-490 ◽  
Author(s):  
Austeclinio L. de Farias Neto ◽  
José Branco de Miranda Filho
Keyword(s):  
Zea Mays ◽  
Plant Height ◽  
Inbreeding Depression ◽  
Zea Mays L ◽  
Plant Traits ◽  
The Other ◽  
Branch Number ◽  
Tassel Branch Number ◽  
Ear Height ◽  
Selection For

The present work was based on the evaluation of full sib and S1 progenies from the maize (Zea mays L.) population ESALQ-PB1 after six cycles of divergent selection for tassel size. The following traits were analyzed: plant height , ear height, tassel branch number, tassel length, and tassel weight. For all traits, the experimental units were means of three plants per plot. Progenies were evaluated in eleven experiments (completely randomized blocks) with three replications in Piracicaba -- SP, Brazil. Means of inbred (m1) and non-inbred (m0) progenies were used to estimate inbreeding depression (I = m1 -- m0) and the contribution of homozygotes (mu0 + a*) and heterozygotes (d*) to the population mean. Considering the five traits under study, inbreeding depression varied from 1.9 to 15.9% but significance for that effect was detected only for plant height. Plant traits exhibited higher depression than tassel traits; and tassel branch number seems to be more sensitive to inbreeding than the other two tassel traits. Except for plant height, it was apparent that inbreeding depression was higher in the subpopulation negatively selected for tassel size (T--). Estimates of A = mu0 + a* and d* indicate a smaller effect of dominance deviations for all traits, as compared to the contribution of homozygotes. Significant variability among progenies was detected in most instances.

Sign in / Sign up

Export Citation Format

Share Document