88 Journal on Processing and Energy in Agriculture 23 (2019) 2 Biblid: 1821-4487 (2019) 23; 2; p 88-95 Original Scientific Paper UDK: 581.48 Originalni naučni rad STABILITY OF GRAIN NUMBER PER PANICLE IN A COLLECTION OF AUTUMN OAT ( AVENA SATIVA L.) GENOTYPES STABILNOST BROJA ZRNA PO KLASU U KOLEKCIJI OZIMIH GENOTIPOVA OVSA ( AVENA SATIVA L.) Emilian MADOSA * , Sorin CIULCA*, Giancarla VELICEVICI * , Adriana CIULCA * , Constantin AVADANEI *, Lavinia SASU ** * Banat`s University of Agricultural Sciences and Veterinary Medicine „King Michael I from Romania”, Timisoara, Calea Aradului 119, Romania ** ”Vasile Goldis” Western University, Arad, B-dul Revolutiei 94, Romania e-mail: madosae@yahoo.com ABSTRACT The purpose of this study is to examine the stability of grain number per panicle in a collection of autumn oat genotypes under different climatic conditions. The biological material analysed consisted of 73 oat genotypes studied over a period of three years. The experimental data were obtained by biometric measurements and subsequently processed using the following linear regression models: Finlay-Wilkinson, Hardwick-Wood, Muir and Wrike. The grain number per panicle obtained varied according to the annual climatic conditions both as means and the intrapopulational variability. The Jefferson, Carrie and Florina cultivars, as well as the 4458, PA 725-4743 and PA 822-818 lines, exhibited a high dynamic stability associated with the above-average values of the grain number per panicle. Relative to this character, a total 53.10 % of the genotype x environment interaction is due to the heterogeneity of variances. Key words: oats, stability, grain number per panicle. REZIME Svrha ove studije je da se ispita stabilnost broja zrna po klasu u kolekciji ozimih genotipova ovsa u različitim klimatskim uslovima. Analizirani biološki materijal sastojao se od 73 genotipa ovsa, ispitivanih tokom perioda od tri godine . Eksperimentalni podaci su dobijeni biometrijskim merenjima i naknadno obrađeni korišcenjem sle decih modela linearne regresije : Finlai-Vilkinson, Hardvick-Vood, Muir i Vrike. Broj zrna po dobijenim klasu varirao je u zavisnosti od godišnjih klimatskih uslova i po srednjoj vrednosti i kao intrapopulacijska varijabilnost. Sorte Jefferson, Carrie i Florina, kao i linije 4458, PA 725-4743 i PA 822-818, pokazale su visoku dinamičku stabilnost povezanu sa iznad-prosečnim vrednostima broja zrna po klasu. U odnosu na ovaj pokazatelj, ukupno 53,10% interakcije između genotipa x i okoline je rezultat heterogenosti varijanse. Ključne reči: ovas, stabilnost, broj zrna po klasu. INTRODUCTION The interaction between the oat genotype and the environment exerts significant effects on the grain production and quality. Under different environmental conditions, oat genotypes vary relative to the production of grains, the mass of 1000 grains, the percentage of chaff, the starch content and the β-glucan content. Oat genotypes with high quality and production values, as well as a high stability of characters, have the ability to pass these attributes to their progeny (Mut Zeki et al. 2018). The production performance of autumn oat genotypes can be evaluated according to precocity, winter resistance, plant height, panicle length, spike number per panicle, grain number and weight per panicle and the mass of 1000 grains. These plant characters are of vital importance to the selection of genotypes in both breeding and hybridization programs (Panayotova Galina et al., 2018). The diversification of production characters has also been attempted through the use of biotechnology in breeding programs. The value of regenerated plants obtained from mature embryos is assessed relative to the height of plants, the length of panicles, the number of spikes per panicle, the number of grains per panicle, the weight of grains per panicle and the weight of 1000 grains. In addition to the morphological features of productivity, it is also necessary to evaluate the quality properties such as the protein and fat contents. Regenerated plants may be higher, featuring longer panicles and larger grain number per panicle (Dyulgerova Boryana and Savova Todorka, 2017). Of the climate factors exerting a major influence on the panicle productivity, drought is the most important. Due to genetic variability, some oat genotypes tolerate drought better than others. The data on valuable oat genotypes can be collated by different genetic variability assessments and measurements of the stress factor effect on the specific morphological character of the plant. One of the characters recommended for evaluation is the grain number per panicle, alongside the grain mass per panicle, i.e. the mass of 1000 grains. The stress factor sensitivity index and the tolerance index (Atefah Zaheri and Sohbat Bahraminejad, 2012) are the stability indicators which should be determined. The stability of panicle productivity can also be examined by comparing some hybrid populations with parental forms. Assessments of generational behaviour over a period of several years have been performed by studying the number of panicles per plant, the number of grains per panicle and the weight of grains per panicle. The combinatorial ability of progenitors has been found to be of paramount importance to the manifestation of certain characters and their response to environmental factors (Igor Pirez Valério et al., 2009). Relative to the character stability in autumn oats, correlations between specific characters can facilitate their determination and better comprehension. A number of studies conducted in Turkey used linear stability regressions and determinants as stability indices for oat character description. The characters examined were affected differently by the interaction between oat genotypes and the environment. The coefficients of correlation obtained for the characters studied differed according to environmental conditions. Furthermore, a correlation was found between the productivity