Ukraine ОIL CONTENT IN CHICKPEA SEEDS OF THE NATIONAL COLLECTION OF

UKRAINE Abstract: Chickpea ( Cicer arietinum L.) is an important legume crop grown and consumed worldwide. Oil content in chick pea seeds ranges from 4 % to 7 % according to various data sources. Considering the interest of breeders in this issue, as well as for the purpose of inventory of the presented chickpea genetic material in the collection of the National Center for Plant Genetic Resources of Ukraine, these studies were carried out. Field experiments were carried out in 2016-2018 in the scientific crop rota tion of the Plant Production Institute n.a. V. Ya. Yuriev of NAAS (Kharkiv, Ukraine). 43 samples (21 - kabuli type and 22 - desi type) of different ecological and geographical origin were studied. Oil content in chickpea seeds was determined using gravimet ric method of S. V. Rushkovsky (Yermakov, 1987) in the laboratory for genetics, biotechnology and quality of the Plant Production Institute n.a. V. Ya. Yuriev of NAAS. On average, over the years of study, in the kabuli type accessions, the oil content level in the seeds made 7.08 %; for accessions - 6.05 %. The range of variability of this trait for the kabuli chickpea ranged from 5.22 % to 8.69 %, and for desi - from 4.40 % to 7.26 %. A low variability of the studied trait was noted for both the kabuli ( V = 6.88-15.04 %) and for desi ( V = 8.98-14.15%) chickpea cultivars. The advantage in terms of oil content in seeds, regardless of the growing con -ditions, was retained for the kabuli type. The accessions with the maximum level of the “oil content in seeds” trait manifestation were selected as “reference” for each type: for kabuli - variety Pamyat (Ukraine) - 7.95 %, for desi - Yarina (Ukraine) - 7.13 %. The best oil-bearing chickpea samples can be used in specialized programs to create new genotypes with a higher oil content in

consumers, as well as for the purpose of inventorying the available genetic material of chickpea from the NCPGRU's core collection, this study was designed and conducted. There were also issues of a scale for assessing the oil content in seeds, identification of check accessions for further studies and sources of high oil content in seeds for breeding, which became our objectives.
Material and Methods. In 2016-2018, the oil content in chickpea seeds from the NCPGRU's core collection was analyzed for the first time. In 2016, 24 accessions were studied 12 kabuli (with light seeds) and desi (with dark seeds) accessions of different eco-geographical origin. These accessions have been investigated at the NCPGRU for many years, and some of them were previously chosen as check accessions for different valuable traits, such as yield capacity, resistance to ascochytosis, seed size, early ripening, high protein content, cooking property, etc. [18]. In 2017-2018, the assortment of the studied accessions was expanded to 43 accessions (21 belonged to the kabuli-type and 22 -to the desi-type) due to local accessions of different origin.
According to the State Standard for identifying sources of valuable traits in the NCPGRU's collections, accessions whose values are by l 15 % higher than the average across the sample are distinguished as sources 1 .
The field experiments were carried out in the scientific crop rotation of the Plant Production Institute named after V.Ya. Yuriev, Kharkiv, Ukraine in 2016-2018. The forecrop was winter wheat. The field experiments were conducted in accordance with the "Guidelines for Studying the Genetic Resources of Grain Legumes" (2016) 2 .
The oil content in chickpea seeds was determined by S. V. Rushkovsky's gravimetric method 3 in the Laboratory of Genetics, Biotechnology and Guality of the Plant Production Institute of named after V. Ya. Yuriev of NAAS.
The weather conditions during the vegetation periods of the 3 study years varied significantly. 2016 was characterized by waterlogging during the chickpea flowering and ripening periods (June-August): the precipitation amount was 143.7 mm, which is by 60.6 % higher than the multi-year average for this period, while both 2017 and 2018 were hot and dry, with 43 % and 60.9 % of rainfall related to the multi-year average, respectively. In 2018, the average daytime temperature in June-August reached 29.6-35.5 °С and was accompanied by heavy rains during the seed setting and filling. Of the 3 study years, 2016 was unfavorable for the chickpea growth and development, and 2017 and 2018 were closer to the optimum for this crop, although they were marked by high temperature and drought.
Results: The 2016 results showed that the average oil content across the sample of chickpea seeds was 7.72 %, ranging 6.79 to 8.57 % in the kabuli accessions and 5.02 to 7.26 % in the desi ones (Table 1), which is significantly higher than the values reported by other researchers. For example, Shah et al. reported that the oil content in chickpea seeds from Pakistan was 3.54 % [22]; in Avola et al.'s publication it was 4.36 % for Italian accessions [23].
Seven out of the 12 kabuli accessions investigated in 2016 had an oil content within the average across the test sample (7.16 %), and in 2 accessions the values exceeded the average by more than 15 %: Ukrainian cultivars Dniprovskyi Vysokoroslyi (8.27 %) and Smachnyi (8.52 %). As to the desi-type, 3 accessions had the intermediate contents: CDC Anna (7.26 %), Krasnokutskiy 123 (7.21 %) and Koloryt (7.11 %). None of the desi accessions exceeded the average by more than 15 %.
The three-year study (2016-2018) of the oil content in chickpea seeds in the conditions of the Eastern Forest-Steppe of Ukraine showed that in this test sample the average was 7.08 % and 6.05 % across the kabuli and desi accessions, respectively ( Table 2).
The oil content range in chickpea seeds over the study years was 5.22 % to 8.69 % and 4.40 % to 7.26 % for the kabuli and desi types, respectively. The oil content in seeds across the entire sample ranged 4.40 % to 8.69 %. It should be noted that in 2017 and 2018, compared with 2016, the oil content range in seeds expanded significantly, which can be attributed both to an increase in the number of accessions in the sample and to a possible influence of the plant vegetation conditions. Thus, in 2016 the oil co-tent was for the kabuli-type was 6.79 % -8.52 %, and in 2017 and 2018 -5.74 % -8.69 % and 5.22 -8.65 %, respectively. The same trend was noted for the desi-type: in 2016 the oil content amounted to 5.02 % -7.26 %, and in 2017 and 2018 this parameter was in the range of 4.70 -7.20 % and 4.40 % -7.07 %, respectively.
Analysis of the 2016 data gave a low coefficient of variation of the "oil content in seeds" trait in the kabuli (CV = 6.88 %) and desi (CV = 8.98 %) accessions, which can be attributed either to a high homogeneity of the sample or to a consequence of its small size and effects of the weather conditions. Avola et al. (2012) noted that the oil content varied slightly in different accessions, but increased significantly during seed cooking [23]. Ukrainian researchers also reported a weak variability in the trait [17]. When the size of the sample increased to 43 accessions in 2017 -2018, the coefficient of variation rose for the both types, but it did not fall outside of the average limits.
Working with genetic resources, one should evaluate large numbers of collection accessions, which requires a scale with a variability range of the trait under investigation. To develop such a scale, we reviewed literature data published by researchers from different countries ( Table 3).
After developing the scale, it became possible to evaluate chickpea accessions of the core collection of the National Center for Plant Genetic Resources of Ukraine for the oil content (Fig. 1).

T a b l e 1. Oil Content in Chickpea Seeds Harvested in 2016
No in the National As a result, the accessions under investigation were categorized according to this scale. It was found that among the kabuli accessions, accessions with a moderate (10 accessions, 48 % of the entire kabuli sample) and high (8 accessions; 36 %) oil content in seeds were overwhelming. As to the desi-type, accessions with a low and moderate oil content in seeds were the most numerous (9 accessions of each type; 41 %).

Catalogue of Ukraine
The high stability of the trait under investigation allowed us to identify sources of high oil content in seeds. These accessions can be used in specialized breeding programs to create new genotypes with high oil content in chickpea seeds. T. M. Shah noted a more conspicuous increase in oil level when parental pairs of different morphological types (kabuli and desi) are crossed than when accessions belonging to the same morphological type are crossed [28]. Therefore, selection of accessions -sources of high oil content belonging to different types is a pre-requisite for further breeding to improve the nutritional qualities of chickpea.
A two-year study of accessions is sufficient to identify sources of high oil content in seeds. In 2017-2018, seeds of the kabuli accessions contained 5.78 % -7.95 % (mean = 6.95 %) of oil. A high oil content (7.00 -7.99 %) was recorded for 10 test kabuli accessions (47.62 %), which we recognized as sources of high oil content. These are Pamiat (Ukraine), NEC 2184 (Iran), UD0502111 (Russia) and others. There were no accessions with very high (above 8.00 %) oil content. The maximum oil level during the two study years was observed in Pamiat (Ukraine; 7.95 %), NEC 2184 (Iran; 7.79 %) and UD0502111 (Russia; 7.77 %).
As to the desi-type, the average oil content for the two study years was 5.89 %. A high oil level was only observed in 1 accession -Yaryna (Ukraine) -7.13 %. The most of the desi accessions had a moderate (40.91 % of the sample) or a low (50 %) content of oil. Among the studied desi accessions, 2 accessions with high oil content in seeds were identified: Yaryna (7.13 %) and Koloryt (6.91 %); the both cultivars have been bred in Ukraine and can be sources of this trait in the desi-type.
The accessions with the maximum expression of the trait of interest were selected as check accessions for their morphological types: cultivar Pamiat (Ukraine) for the kabuli-type and cultivar Yaryna (Ukraine) for the desi-type.
Unidirectional and similar fluctuations in the oil content were noted in both kabuli and desi accessions, depending on the year conditions (Fig. 2).
We found that the kabuli-type is superior to the desi-type in terms of oil content in seeds, regardless of the growing conditions.

Conclusions.
Thus, our studies showed that the chickpea accessions of the NCPGRU's collection had a high oil content in seeds, which increases their value for breeding programs to develop new food cultivars for a balanced diet.
Valuable sources of high oil content in seeds (Pamiat (Ukraine), NEC 2184 (Iran) and UD0 502111 (Russia) belonging to the kabuli type as well as Yaryna and Koloryt (Ukraine) belonging to the desi-type were identified. We recommend including them in breeding programs to develop new chickpea cultivars.
We experimentally developed the scale that is recommended for classification of chickpea accessions by oil content in seeds.