Evaluation of environmental plasticity and stability of common gourd varieties by major valu-able economic parameters in the forest steppe of Ukraine

Abstract

The results of studying a set of environmentally plastic as well as fruit performance- and quality-stable common gourd (Cucurbita maxima Duch.) varieties Zhdana, Yuvilei, Slavuta, Poliovychka for growing in the forest-steppe of Ukraine are presented. The results distinguished common gourd varieties Yuvilei and Poliovychka characterized by high adaptability for the total yield as well as the total sugar and provitamin A contents in fruit pulp.

Purpose. To select high-plastic as well as fruit performance- and quality-stable common gourd varieties for growing in the forest-steppe of Ukraine.

Materials and methods. The study was carried out in the experimental field of the Department of Vegetable Production of the separated subdivision «Agronomic Experimental Station» of the National University of Life and Environmental Sciences of Ukraine of Ukraine in 2013–2017. We studied common gourd varieties (Cucurbita maxima Duch.) Yuvilei, Slavuta and Poliovychka with the most common variety Zhdana as a control. The experiments were laid out in compliance with «Research Methods in Vegetable and Melon Growing» (2001). Biochemical analyses were carried out in the Interdepartmental Laboratory of Biochemical Analyses of the National University of Life and Environmental Sciences of Ukraine of Ukraine by standardized methods: the total sugar content – by Bertrand’s method; carotene A content – by Murray’s method. The results were statistically processed, as BA Dospekhov described. The variability and adaptability of traits were determined by AV Kilchevskiy and LV Khotyleva’s and SA Eberhart and WA Russell’s methods.

Results and discussion. In the study years, the highest yields of fruits were given by common gourd varieties Poliovychka (33.8 t/ha) and Yuvilei (30.6 t/ha). The greatest levels (4.0 and 0.8) of the general adaptability (GA) were observed in varieties Poliovychka and Yuvilei. Poliovychka was the best in terms of the specific adaptability (SA) – 5.0. Varieties Poliovychka and Slavuta were breeding-valuable (BV) – 26.2 and 15.2, respectively. Variety Zhdana was the least valuable (7.1). Slavuta and Yuviley had the highest total sugar contents: 9.0 and 8.3%, respectively. The high GA for this trait was intrinsic to Slavuta – 0.8. All the varieties were stable by SA (0.1–0.9), except for Poliovychka (2.3). Slavuta and Zhdana were distinguished as BV genotypes (6.6 and 5.8, respectively); Poliovychka was the least valuable (0.5). The annual average provitamin A content in fruits of common gourd varieties varied 7.2 to 11.2 mg/100 g. A significant increase in this index was observed in Zhdana and Yuvilei – 11.0–11.2 mg/100 g. Slavuta and Poliovychka were the most adapted to specific growing conditions: 0.7 and 1.6, respectively. Yuvilei and Zhdana were highly BV genotypes (6.3 and 4.2, respectively) by provitamin A content; variety Slavuta was low BV (3.3).

Conclusions. The study results allowed us to select the following varieties of common gourd:

1. Poliovychka characterized by high adaptability for the total fruit yield of around 33.8 t/ha (GA – 4.0, SA – 5.0, Sgi – 6.6, bi – 0.3, BV – 26.2).

2. Slavuta and Yuvilei with high quality parameters of fruit pulp and high adaptability for the total sugar content – 9.0 and 8.3%, respectively (GA 0.8 and 0.1, respectively; SA 0.5 and 0.9, respectively; Sgi 7.8 and 11.5%, respectively; bi 0.9 and 1.2, respectively; BV 6.6 and 3.9, respectively) and provitamin A content: 11.2 and 6.3 mg/100 g, respectively (GA2.3 inYuvilei; SA 2.4 and 0.7, respectively; Sgi 12.9 and 13.7, respectively; bi 0.5 and 1.2, respectively; BV 6.3 and 3.3, respectively).