Correlation of breeding traits that determine productivity of chickpea ( Cicer arietinum L.) accessions from the VIR collection in the conditions of Tambov region

Increasing global temperature recently leads to climatic changes towards more drought conditions over large areas, so drought resistant plants should be wider cultivated. Chickpea is a drought resistant crop commercially cultivated in 2013 at 800 000 ha in some region of the Russian Federation with periodic droughts, except the Tambov region, though its geographic and climatic conditions could be appropriate for chickpea growing. For the first time in the Tambov region we investigated the formation of breeding traits that determine seed productivity in 629 chickpea accessions of different origin, including 44 countries, from the VIR (All-Russian Research Institute of Plant Industry, St. Petersburg) World Collection which were selected due to prior wide geographic testing in other Russian regions and abroad. Using statistical methods, i.e. factor, dispersion analysis and clustering, we defined breeding and noticeable traits, the influence of sowing norm, and the countries which were the most perspective as originators of chickpea. It is shown that the number of branches of the 2 nd order, the number of pods per plant, plant height, the length of growing period mainly contributed into determining productivity of chickpea plants in the environmental conditions of the Tambov region. The weight of 1000 seeds had a positive relationship with the period from flowering to ripening. A significant association between the weight of seeds per plot and the number of plants was observed with the maximum rate found at 70-80 plants per plot. The variability of accessions in plant dray weight was the greatest and reached the value of Cv = 98.3 %. A total of 73 % of the variability of the investigated traits were influenced by three factors. The first one causing 38 % of variability comprised of a block of correlated traits, namely the number of branches of the 1 st and 2 nd order, the number of pods per plant and plant dry weight, which were associated with the number of seeds per plant. The second one of a 25 % influence included the periods from germination to flowering and from flowering to ripening, the height of the lower bean attachment and the plant height, and the third one with a 10 % effect on variability was the weight of 1000 seeds. In 330 studied forms the bean cracking rate was 10 % that met the standards of Volgogradskii 10 variety, in 202 accessions it exceeded 10 %, and 96 accessions were resistant to bean cracking being valuable for breeding. A total of 147 accessions were not affected by fusarium wilt, and another 120 accessions were very weakly attacked and damaged. By clustering we identified three groups of countries where the forms with higher seed weight per plant and weight of 1000 seeds as the most economically valuable traits were originated from. Accessions from the United States were characterized by larger weight of 1000 seeds and weight of seeds per plant, while in accessions from the former Soviet Union, Bulgaria and Afghanistan the weight of 1000 seeds and the weight of seeds per plant were low. For the rest countries both these parameters were close to average values. So in the Tambov region the k-3720, k-3721, k-3740, k-3771, k-3783, k-3785 from Syria; k-604, k-2340 from Turkey; k-431, k-437, k- 2176 from Mexico; k-1188, k-1335, k-1480, k-2197, k-2397 from Russia; k-2144 from Afghanistan; k-1491, k-1724, k-1727 from Uzbekistan and k-2597, k-2949 from the U.S. are the most perspective form in breeding for seed productivity. A total of 178 most prospective accessions were further tested in 2011-2013.