118 Bulletin UASVM, Agriculture 65(1)/2008 pISSN 1843-5246; eISSN 1843-5386 „PER SE” VALUE IN SOME SYNTHETIC VARIETIES OF CORN CREATED AT SCDA TURDA Gulea A, VoichiŃa Ha, Iustina LobonŃiu, I. Ha, I. Oroian, I.A.Pop StaŃiunea de Cercetare i Dezvoltare pentru Creterea Bovinelor Tg. Mure The Research and Development Station for Cattle Breeding Târgu Mure 1227, Principala Street, Singeorgiu de Mures, 547530, MS, tel.: +40 265 319006, e-mail: guleadani@yahoo.com Key words: corn, synthetic varieties, breeding, “per se” value ABSTRACT. Using different breeding methods (mass selection, recurrent selection full -SIB and half – SIB, recurrent selection with testcross) year by year corn breeder aims to improve genetic heritage of synthetic population, to amplify the additive effect of gene interaction inside the population in order to simplify his creation work for superior inbred lines and hybrids. This paper presents results obtained in two location trials designed and planted in 2006 and 2007 using some corn synthetic populations created at SCDA Turda. There were registered data concerning yield, lodging, and earliness in assay to get a better initial genetic material for further breeding work. Some of the synthetics have prooved good tolerance to water stress but their yielding capacity is lower then in case of commercial hybrids, on a very significant level. INTRODUCTION The success obtained by Shull and East at the beginning of the past century on inbreeding and heterosis, incomparably greater than results obtained before through classic methods caused, for a relative long period of time, selection and improvement of genetic material in corn synthetics to be neglected. For the first time, LONNQUIST (1949) reveals the necessity of improvement in corn populations in order to raise favorable gene frequency and to develop more valuable inbred lines. In the middle of XX-th century corn breeders demonstrate that corn populations comprise a significant genetic variability of additive nature. In our country, the importance of genetic variability and amelioration on initial germplasm it is emphasized by HAS (2004), ILLICEVICI (1994), LUCIA ROMAN (1976), SUBA (1970). Corn synthetics are free pollination populations obtained by cross-breeding auto- pollinated individuals or inbred lines, maintained by mass selection methods in isolated plots (HALLAUER, 1966). The purpose of corn synthetics and composites is to concentrate in the same germplasm special and valuable traits from local populations and inbred lines in a continuous improving process. This way, desired genes are collected in a single germplasm source, easier to maintain, and amelioration of genetic resources is cheaper and easier to conduct (ROMAN, 1976) The genetic value of maize populations it is improved by various selection schemes applied inside the populations and between different populations. “Per se“value of corn synthetics is of great importance because inbred lines are selected for recombination depending on both their “per se” value and productivity of hybrids resulted from testcrosses.