Recurrent Selection for Reduced Tassel Branch Number and Reduced Leaf Area Density above the Ear in Tropical Maize Populations 1

Crop Science ◽  
1987 ◽  
Vol 27 (6) ◽  
pp. 1150-1156 ◽  
Author(s):  
K. S. Fischer ◽  
G. O. Edmeades ◽  
E. C. Johnson
Keyword(s):  
Leaf Area ◽  
Recurrent Selection ◽  
Tropical Maize ◽  
Branch Number ◽  
Area Density ◽  
Leaf Area Density ◽  
Maize Populations ◽  
Tassel Branch Number ◽  
Selection For

scholarly journals Genetic correlation between traits in the ESALQ-PB1 maize population divergently selected for tassel size and ear height

2001 ◽  
Vol 58 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Austeclínio Lopes Farias Neto ◽  
José Branco de Miranda Filho
Keyword(s):  
Genetic Correlation ◽  
Correlation Coefficients ◽  
Divergent Selection ◽  
Phenotypic Correlation ◽  
Base Population ◽  
Branch Number ◽  
Maize Population ◽  
Tassel Branch Number ◽  
Ear Height ◽  
Selection For

Full-sib and selfed (S1) progenies were obtained from sub-populations of ESALQ-PB1, divergently selected for tassel size (T+ and T-) and ear height (E+ and E-), and used for estimating genetic and phenotypic correlation coefficients between traits. The analyzed traits were: EW- total ear weight (g/plant), PH- plant height (cm), EH- ear height (cm), TB- tassel branch number and TL- tassel length. The highest genetic (rG) and phenotypic (rF) correlation was observed for the combination PH x EH, as expected, with average of 0.800 and 0.778, respectively over sub-populations and locations. It is apparent that divergent selection for tassel size did not affect greatly the correlation between PH and EH in the full sib progenies, but in the inbred progenies the correlation was smaller in the sub-population selected for larger tassels. Genetic correlation between PH and EH with tassel traits was always positive but ranged from 0.020 to 0.668 in Piracicaba and from 0.06 to 0.309 in Rio Verde. Genetic correlation between PH and EH with yield (EW) also was positive in the range of 0.087 to 0.503. EH showed higher correlation with EW in relation to PH x EW and differences were larger in the sub-populations divergently selected for ear height. Correlation between tassel traits with other traits was positive in most of instances and a lack of consistency was observed among sub-populations. Generally the coefficients of genetic and phenotypic correlation differed substantially from the estimates in the base population ESALQ-PB1 before divergent selection for tassel size and ear placement. Divergent selection affected the correlation between traits under unpredicted and varying magnitudes.

scholarly journals Reciprocal recurrent selection effects on the genetic structure of tropical maize populations assessed at microsatellite loci

2003 ◽  
Vol 26 (3) ◽  
pp. 355-364 ◽  
Author(s):  
Luciana Rossini Pinto ◽  
Maria Lucia Carneiro Vieira ◽  
Claudio Lopes de Souza Jr. ◽  
Anete Pereira de Souza
Keyword(s):  
Genetic Structure ◽  
Microsatellite Loci ◽  
Recurrent Selection ◽  
Selection Effects ◽  
Reciprocal Recurrent Selection ◽  
Tropical Maize ◽  
Maize Populations

scholarly journals STUDY ON INDIRECT ESTIMATING LEAF AREA DENSITY

2006 ◽  
Vol 71 (603) ◽  
pp. 111-117
Author(s):  
Ai KADAIRA ◽  
Harunori YOSHIDA ◽  
Daisuke MURAKAMI ◽  
Mamiko ITOU
Keyword(s):  
Leaf Area ◽  
Area Density ◽  
Leaf Area Density

Effect of sward structure of two tropical grasses with contrasting canopies on light distribution, net photosynthesis and size of bite harvested by grazing cattle

1982 ◽  
Vol 33 (2) ◽  
pp. 187 ◽  
Author(s):  
MM Ludlow ◽  
TH Stobbs ◽  
R Davos ◽  
DA Charles-Edwards
Keyword(s):  
Leaf Area ◽  
Growth Regulators ◽  
Light Distribution ◽  
Trimethylammonium Chloride ◽  
Tropical Pastures ◽  
Area Density ◽  
Tropical Grasses ◽  
Bite Size ◽  
Leaf Area Density ◽  
Grazing Cattle

Our aim was to determine whether increasing the sward density of tropical pastures, for the purpose of enhancing the size of bite harvested by grazing cattle, would reduce yield by affecting light distribution andcanopy photosynthesis. The growth regulators (2-chloroethy1)trimethylammonium chloride (CCC) and gibberillic acid (GA) were used to alter the leaf area density of the tussock-forming grass Setavia sphacelata and of the sward-forming grass Digitaria decumbens. GA increased plant height, the length of stem internodes, and the size of bite harvested by cattle. On the other hand, CCC decreased canopy height, and increased leaf area density and bite size. The variation of leaf area density, investigated experimentally by using growth regulators (5-25 m-1) and theoretically by simulation modelling (5-40 m-1), had no significant effect on either leaf or canopy photosynthetic characteristics. Hence we believe that there would be a negligible reduction in yield of these tropical grasses if their leaf area densities were increased up to a value of 40 m-1, which exceeds those of temperate pastures. Such increases in leaf area density may increase animal production from tropical pastures where bite size limits daily intake of forage. The agricultural implications of the findings are discussed.

scholarly journals Recurrent selection for wider seedling leaves increases early biomass and leaf area in wheat (Triticum aestivum L.)

2014 ◽  
Vol 66 (5) ◽  
pp. 1215-1226 ◽  
Author(s):  
L. Zhang ◽  
R. A. Richards ◽  
A. G. Condon ◽  
D. C. Liu ◽  
G. J. Rebetzke
Keyword(s):  
Triticum Aestivum ◽  
Leaf Area ◽  
Recurrent Selection ◽  
Triticum Aestivum L ◽  
Selection For
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