Is there any relation between quantitative traits interesting for ornamental breeding and genome size in dog roses (Rosa sect. Caninae)?

Abstract

To define participation of genome size as well as most important environmental factors in
variability of quantitative characters interesting for ornamental breeding, a collection of wild
dog roses (Rosa sect. Caninae) from Malé Karpaty mountains (localities Modra – Pažite and
Vrbové – Baraní dvor) and Zobor hills (locality Zobor – Lyžiarska lúka) were analysed. We found
a large variability in percentage of leaves longer than 70 mm (16–58%) and those of dark-green
colour (28–78%), portion of half-full flowers (0–6%) and those of intense pink colour (0–100%),
and percentage of hips longer than 20 mm (0–45%) and those of intense red colour (18–48%),
among shrubs. Their genome size ranged from 2.33 to 2.92 pg. Our map survey revealed stagni-
eutric cambisols in Modra – Pažite, haplic luvisols on loess in Vrbové – Baraní dvor, and rendzic/
chromi-rendzic leptosols in Zobor – Lyžiarska lúka (increasing soil quality from stand to stand).
Leaves and flowers grew in conditions of average temperature 15.3 °C (Modra – Pažite and Zobor
– Lyžiarska lúka) and 14.5 °C (Vrbové – Baraní dvor). Precipitation ranged from approximately
300 mm in Modra – Pažite to 400 mm in Zobor – Lyžiarska lúka. Average temperature for hip
formation varied from Zobor – Lyžiarska lúka (19.6 °C) to Modra – Pažite (20.4 °C). In this period,
precipitation sum was round 200 mm in Zobor – Lyžiarska lúka and approximately 250 mm in the
rest two stands. Quantitative traits of all dog roses were generally less correlated to genome size
and environmental factors. However, in R. canina genotypes, leaf length was determined mainly
by genome size (r = 0.437) and temperature (r = –0.316), and leaf colour by temperature (r = 0.777)
and precipitation (r = 0.557), flower richness only by temperature (r = –0.320), flower colour by
temperature (r = 0.606) and soil quality (r = –0.559), and hip colour was defined mainly by
precipitation (r = 0.588), then by temperature (r = 0.427) and genome size (r = –0.362); but
no factor had important influence on hip length. We can conclude that except for leaf size, all
analysed quantitative traits were mainly determined by environmental factors.