Correlation between certain characters for earliness in hybrids produced on systematic heterozygous series

Characters for earliness were studied on hybrids produced on two heterozygous series with different vegetation periods (F564 x HMv404 and CE187 x A632), using 4 pollinator lines (W117, A340, HMv 09 and B37) in each case. The experiments were set up at Martonvasar in a random block design in 4 replications in 1979 and 1980. For each heterozygous series 1920 plant data were evaluated for the following characters:

1. Number of days from sowing to 50% tasseling
2. Number of days from sowing to 50% silking
3. Moisture content at harvest
4. Total number of leaves
5. Number of leaves above the ear.

The mean values of the characters examined are shown in Table 1. The effect of the year was significant at the 0.1% level for the number of days from sowing to 50% tasseling and 50% silking and for the moisture content at harvest, but was not significant for the total number of leaves or the number of leaves above the ear. The interaction of heterozygous series x year was only significant at the P = 0.1% level for the moisture content at harvest, while this interaction cannot be demonstrated for the other characters. The data show that in both years there was considerable deviation in the earliness indices. In 1980 flowering was an average of 15 days later than in 1979. The delay in flowering was associated with an increase in the moisture content at harvest, but there was little change in the total number of leaves or the number of leaves above the ear. It is interesting to note that for the hybrids produced on both heterozygous series the characters examined changed in a similar manner due to the effect of the year.

Table 1. Mean values of earliness indices.
 
 
F564 x HMv404
CE187 x A632
Character 1979 1980 1979 1980
No. days to 50% tasseling 70.59 85.67 73.36 88.35
No. days to 50% silking 73.79 88.71 75.59 90.80
Moisture at harvest, % 30.16 34.83 29.66 35.64
Total no. of leaves 15.81 15.78 16.99 16.99
No. of leaves above ear 5.02 5.04 5.81 5.85

Table 2. Correlation between certain characters for earliness in hybrids produced on systematic heterozygous series. Martonvasar, 1979, 1980.
 
 
Heterozygous Series
 
F564 x HMv404
CE187 x A632
Pairs of Characters for Earliness 1979 1980 1979 1980
1. No. days to 50% tasseling        
- No. days to 50% silking 0.963 0.944 0.971 0.900
- Moisture at harvest, % 0.901 0.786 0.870 0.807
- Total no. of leaves 0.758 0.895 0.581 0.825
- No. of leaves above ear 0.673 0.714 0.602 0.765
2. No. days to 50% silking        
- Moisture at harvest, % 0.903 0.764 0.894 0.787
- Total no. of leaves 0.758 0.859 0.472 0.822
- No. of leaves above ear 0.654 0.653 0.502 0.731
3. Moisture at harvest, %        
- Total no. of leaves 0.603 0.676 0.516 0.699
- No. of leaves above ear 0.378* 0.545 0.508 0.641
4. Total no. of leaves        
- No. of leaves above ear 0.768 0.772 0.817 0.927

*Significant at the 1% level; (all others significant at 0.1% level).

The correlation between the different characters for earliness can be seen in Table 2. The correlation is highly significant for both years and for hybrids produced on both heterozygous series. The number of days from sowing to 50% tasseling and 50% silking and the moisture content at harvest show a closer correlation with the total number of leaves than with the number of leaves above the ear. Years with different weather conditions had little or no effect on the correlation between the earliness indices.

T. Szundy and I. Kovacs


Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.

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