Interrelationships of Seedling Vigor Criteria of Wheat under Different Field Situations and Soil Water Potentials1
- Azam Gul and
- R. E. Allan2
The relationships among emergence rate index (ERI), total stand (TS), culm length, coleoptile length, seedling height, root weight, and kernel weight of 93 wheat (Triticum aestivum L. em Thell.) lines and four check cultivars were studied at four different water potentials (—2.2, —6.0, —10.2, and —14.4 bars) in the laboratory and in three eastern Washington field situations (Lind shallow-sown, Lind deep-sown, and Pullman).
The ERI values of the three field tests correlated with one another but they gave small or nonsignificant r values with ERI's from the four laboratory water potential levels. The marked differences in planting depth and water potential level between the field and laboratory could explain the lack of relationship.
Coleoptile length, seedling height, and culm length correlated positively with field ERI. In the laboratory, however, ERI at only —2-2 bars correlated significantly with coleoptile length and seedling height. Kernel weight inconsistently correlated with ERI and gave significant positive r values with field ERI on two occasions but had a significant negative r value with ERI of one laboratory water potential level. In the laboratory, the association between ERI and TS, ERI and root weight, and TS and root weight became progressively closer as the water potential decreased and verified other work that showed fast-rooting lines emerge better than slow ones under low soil-water potential.
As with ERI, significant correlations were found between both TS and coleoptile length and TS and seedling height in field studies. These seedling traits (field) were independent of the TS values obtained at the four water potentials (laboratory). Kernel weight gave low or nonsignificant r values with field and laboratory TS values. Comparisons of both ERI and TS values in field tests and at low water potentials (laboratory) suggest that different genetic systems regulate the growth potential of these wheat lines under these contrasting environments.
The optimum advance from selection should be achieved by testing wheat lines for seedling vigor (ERI, TS) under diverse field situations and at low soil water potentials (—10.2, —14.4 bars).Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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