Morphological Characters Related to Varietal Differences in Tolerance to Deep Sowing in Wheat

In the dry regions, crops are often sown deeper than in the wet regions, because of the relatively high stability of water content of the deep soil layers. However, deep sowing may impair crop emergence and tolerant varieties are, therefore, necessary for successful crop production. The objectives of the present study were to identify and analyze the morphological basis of the varietal difference in tolerance to deep sowing in wheat (Triticum aestivum L.). Several morphological parameters of plumule were measured in five varieties. The varieties used were Hongwang-mai, Ninchun No. 10, Mianyang No. 11, Sϋ 85131 and Haruhikari. Varieties tolerant to deep sowing, Hongwangmai, showed the highest emergence rate under deep sowing in tamped soil. The soil penetration force of plumule represented by ratio of emergence rate in tamped to that in untamped soil correlated with the cross-section area of coleoptile tip (r= -0.929, p0.01). It is confirmed in this study that the varietal difference in the tolerance of wheat to deep sowing is correlated with the final coleoptile length and the cross-section area of coleoptile tip. The final coleoptile length might be determined by the number of longitudinally arranged cells in the coleoptile. The tolerant variety, Hongwangmai, had the longest coleoptile and the smallest cross-section area of coleoptile tip