The pendulum test for screening soybean genotypes for seeds resistant to mechanical damage
1995
Carbonell, S.A.M. | Krzyzanowsky, F.C. (EMBRAPA-National Center for Soybean Research, Londrina (Brazil))
Information on soybean (Glycine max (L.) Merrill) genetic variability relating to the resistance of seeds to mechanical damage is commonly found in the literature, but there is no specific and well accepted method to select for this characteristic. To study the occurrence of this trait, a "Pendulum Test" method, capable of identifying genotypes with seeds resistant to mechanical damage was developed and tested. The apparatus consisted of a free dropping pendulum, which hits individual seeds placed in a depression in a metal plate. Seeds of 12 field-grown soybean cultivars with different degrees of resistance to mechanical damage were harvested at the R7 growth stage, hand threshed and dried to 13 % moisture content. Seeds were then subjected to a pendulum dropped from heights of 11, 13 and 14.5 cm. After the treatment, the seeds were assayed for mechanical damage by the tetrazolium test. Best results were obtained with the 13 cm height impact, which imposed a kinetic energy of 0.32 joule on the seed. This test separated soybean cultivars into three categories of resistance to mechanical damage. The cultivars were classified as resistant, moderately resistant, and susceptible to mechanical damage. The results confirmed the feasibility of using the pendulum test in soybean breeding programmes to identify genotypes with seed resistance to mechanical damage. The genetic variability for seed resistance to mechanical damage among different soybean cultivars was demonstrated
显示更多 [+] 显示较少 [-]