论文部分内容阅读
以27个玉米品种(系)的种子进行浸种、发芽后,考察种子产生双胚苗的状况及发生频率。其结果:供试的27个品种(系)中,出现双胚苗的有10个、占37.04％,品种(系)间双胚苗的自发频率不同,幅度为0.199‰至3.62‰;双胚苗的发生频率表现出如下规律:(1)地方种的自发频率最高,单交种(F_1)次之。(2)马齿型品种高于硬粒型及半马齿型品种(系)。(3)大粒品种(系)高于中、小粒品种(系)。(4)双胚苗的自发频率与籽粒的黄、白无显著差异;双胚苗发生的状况可分为四类:(1)同轴:双生芽同一中胚轴。(2)不同轴而同面:双生芽各有其中胚轴,同位于籽粒正面。(3)不同轴且不同面:双生芽各自有中胚轴,一芽位于籽粒正面,另一芽位于籽粒背面。(4)不同轴且不同方向:双生芽不同一中胚轴,一芽向种子上方长出,另一芽向胚尖下方伸出。
The seeds of 27 maize varieties (lines) were soaked and germinated to examine the status and the frequency of seed germination. The results showed that there were 10 double embryo seedlings (37.04%) in 27 varieties (lines) tested. The spontaneous frequencies of double embryo seedlings varied from 0.199 ‰ to 3.62 ‰, The frequency of seedling showed the following rules: (1) The highest frequency of spontaneous endemic species, followed by single cross (F_1). (2) The dent type is higher than the durum type and half dent type (Department). (3) large grain varieties (lines) higher than medium and small grain varieties (lines). (4) There was no significant difference between the spontaneous frequency of double embryo seed and the yellow and white of the grain; the occurrence of double embryo seedlings could be divided into four categories: (1) Coaxial: double germinate same hypocotyl. (2) The same axis and the same plane: Twin buds have their hypocotyls, with the positive grain. (3) Different Axes and Different Surfaces: The twin buds each have a mesocotyl, with one bud on the front of the grain and the other on the back of the grain. (4) different axes and different directions: different twin mesophyll mesoderm, a bud grows to the top of the seed, another bud protruding below the embryo.