摘要
玉米籽粒的蛋白质含量一般在10%上下,比小麦(13—14%)为低,比水稻(7—9%)为高。但玉米蛋白质总量中醇溶性蛋白占50—60%,这种蛋白质缺乏人或单胃动物营养上必需的氨基酸,特别是赖氨酸和色氨酸。所以,从营养观点来看,玉米的蛋白质品质是比较低的,在稻米和麦粒中,这种醇溶性蛋白质所占的比率分别为5—10%和30—40%,因此,它们的蛋白质品质就比玉米为好。
Opaque-2 kernels on the segregating ears of 11 first backcross selfed progenies differed significantly from their normal sibs in several kernel characteristics.On the average,the opaque types were 6.1%lower in test weight(with a range of 0.6%to 11.8%)and 15%less in kernel density(ranged from 7%to 21.5%)than their respective normals.However,the opaque kernels were generally about 10%larger in size,except only one out of 11 inbreds under conversion.These findings did help us to focus our attention on selection for higher test weight rather than for the size of the kernels.None of the 15 opaque-2 single cross hybrids under yield trial test had surpassed the normal checks.The topmost yielding ohybrid,Ru 11^(3)(o_(2))■_(2)x 75-308/o,giving 7341 kg of grain per hectare,was still 5.9%to 10.0%less than the best normal hybrids.But,all the tested ohybrids had their lysine content on the basis of whole kernel almost doubled the normal.Measured in total amount of lysine in an unit area of land,another Ohybrid 75-308/o_(2)x 52-6/o_(2)produced 35.4 kg of lysine per hectare which was also two times greater than the normal,even though the former gave only 80.7%grain yield of the latter.Among the converted o_(2)inbreds so far tested,the lysine content seemed to be positively correlated with their protein level.This can be used as a supplementary criterion for selection.We have found three types of kernel,—with modified semi-mottling endosperm,normally hard and the typical soft-floury endosperm,on the oears when they were pollinated by two hard endosperm opopulations obtained from CIMMYT.On the basis of whole kernels,the content of lysine and 16 other amino acids were found to be almost equal among these kernel types.Thus,we had made full use of adquate hard endosperm Oto improve the kernel quality of our breeding materials.
作者
李竞雄
石德权
吴秀琴
常碧影
C.H.Li;T.C.Shih;S.G.Wu;P.Y.Schan(Institute of Crop Breeding and Cultivation,Chinese Academy of Agricultural Sciences;Laboratory of Chemical Analysis,C.A.A.S.)
出处
《中国农业科学》
1980年第1期23-29,共7页
Scientia Agricultura Sinica
