A study on the causes of Iris tenuifolin dormancy and the methods for breaking dormancy

Abstract

Abstract: The causes of Iris tenuifolin seed dormancy were studied by the hygroscopicity of seeds, different scarification treatments and germination inhibitor tests. The embryo was not responsible for dormancy, while the seed coats and micropylar endosperm played important roles in reducing germination percentage. Additionally in the seed coats, there were polar germination inhibitors which were soluble in methanol. Sulphuric acid treatment for 60 min or cold-warm stratification (4℃/25℃) for 120 or 150 d effectively promoted germination percentage, from 0 to 51.11%, 36.67% and 40.00%, respectively, and also increased the germination index to 0.45, 0.42 and 0.51. The germination percentage was only 7.78% if the seeds were stratified at 4℃ for 150 d. The main reason why cold-warm stratification was better for germination, was that the mechanical resistance to embryo growth was considerably reduced and the growth potential of embryos was considerably enhanced. In summary, the seed of I. tenuifolin has a physiological dormancy, which is caused by both the mechanical resistance of micropylar tissue and germination inhibitors in seed coats.

CLC Number:

S330.3

ZHANG Dan, ZHANG Jin-zheng, SUN Guo-feng, LI Xiao-dong, HE Qing. A study on the causes of Iris tenuifolin dormancy and the methods for breaking dormancy[J]. Acta Prataculturae Sinica, 2011, 20(6): 109-117.

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