玉米杂种优势的免疫化学预测。

The Genetics Chair, Academy of Agriculture "G. Dimitrov" and the Biology Chair, Institute for Foreign Students, Sofia, Bulgaria.

Theor Appl Genet. 1974 Jan;45(3):91-5. doi: 10.1007/BF00291136.

Heterosis is a complex biological phenomenon. Because of the complex interaction and interrelation between "genes - metabolism - environment", it is hardly possible to expect a clarification of the heterosis phenomenon through simple genetic explanations only (Hagemann et al. 1967).We have followed an immunochemical aspect and method of research. The antigenic analysis of inbred lines and their hybrids was used for studying heterosis and for investigating the possibilities for its prognosis.The heterosis effect was proved under field conditions. Our investigations (Dimitrov et al. 1972) show the presence of four protein fractions in the seed extracts of inbred maize lines, while the heterotic hybrids contain a fifth protein fraction. Antigenie analysis by the method of Grabar and Williams was carried out for a more complete characterization and determination of the specificity of the fractions obtained (Grabar and Williams 1955).The present publication is a result of our research upon maize inbred lines, simple heterotic and nonheterotic hybrids and their backcrosses. A double diffusion in agar gel, according to the Ouchterlony method (Ouchterlony 1958), confirmed the presence of a fifth protein fraction in the heterotic hybrids, which can not be found in the inbred lines or in the nonheterotic hybrids.In the inbred lines we found 3 protein fractions common to all of them, and also a fourth (individual antigen), contained only in the inbred lines that produce a heterosis effect when crossed. It was determined that the carrier of the information for the synthesis of the individual antigen is a nuclear factor.We also determined the conditions under which (after direct and inverse crosses and after crosses in one direction only) heterotic hybrids are obtained. Some backcrosses show a marked heterosis effect connected with the doubling of the factor, carrier of the information for the individual antigen. This fact is important for the scientific verification of the methods for obtaining complex heterotic hybrids.Our results throw some light upon the genetic nature of the heterosis phenomenon.The heterosis effect was determined only for inbred lines whose seed extracts have a precipitation arc against their homologous serum, absorbed with the extract of its partner. This allows for the prognosis of heterosis in maize, i.e. for the determination in advance (through the double immunodiffusion) of the inbred lines and also of the direction of crosses that produce the heterosis effect.The present publication is a continuation of our report (Dimitrov et al. 1972) concerning the research on the nature of heterosis in connection with its prognosis. In our investigation we have accepted as heterotic only hybrids whose seed yield exceeds the seed yields of each of the separate inbred lines being crossed.

杂种优势是一种复杂的生物学现象。由于“基因-代谢-环境”之间的复杂相互作用和相互关系，仅通过简单的遗传解释来阐明杂种优势现象几乎是不可能的（Hagemann 等人，1967 年）。我们采用了免疫化学的研究方法。通过分析自交系及其杂种的抗原性，研究杂种优势，并探讨其预测的可能性。杂种优势效应在田间条件下得到了证实。我们的研究（Dimitrov 等人，1972 年）表明，在自交系玉米种子提取物中存在 4 种蛋白质成分，而杂种优势杂种则含有第 5 种蛋白质成分。采用 Grabar 和 Williams 方法进行抗原分析，对获得的成分进行更全面的特征描述和特异性测定（Grabar 和 Williams，1955 年）。本出版物是我们对玉米自交系、简单杂种优势和非杂种优势杂种及其回交进行研究的结果。根据 Ouchterlony 方法（Ouchterlony，1958 年）进行琼脂凝胶中的双向扩散，证实杂种优势杂种中存在第 5 种蛋白质成分，而在自交系或非杂种优势杂种中则找不到。在自交系中，我们发现了 3 种共同存在于所有自交系中的蛋白质成分，以及第 4 种（个体抗原），仅存在于产生杂种优势效应的自交系中。确定合成个体抗原的信息载体是核因子。我们还确定了获得杂种优势杂种的条件（直接和反向杂交以及单向杂交后）。一些回交显示出与因子加倍相关的明显杂种优势效应，该因子是个体抗原信息的载体。这一事实对于获得复杂杂种优势杂种的方法的科学验证很重要。我们的结果为杂种优势现象的遗传本质提供了一些启示。杂种优势效应仅在其种子提取物与同源血清发生沉淀弧、并被其配偶的提取物吸收的自交系中确定。这使得在玉米中可以预测杂种优势，即在预先确定（通过双免疫扩散）自交系以及产生杂种优势效应的杂交方向。本出版物是我们关于杂种优势本质及其预测的研究报告（Dimitrov 等人，1972 年）的延续。在我们的研究中，我们仅接受那些种子产量超过所杂交的每个单独自交系种子产量的杂种作为杂种优势。