ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 105, No. 4 (2018), p. 349–356
A comparative lowered temperature response in root apex cellular growth of Festuca pratensis and ×Festulolium braunii
Izolda PAŠAKINSKIENĖ, Danguolė ŠVĖGŽDIENĖ
Root apex development was studied in two closely related perennial grasses differing in winter hardiness: highly resistant meadow fescue (Festuca pratensis Huds.) and less hardy ×Festulolium braunii [(K. Richter) A. Camus]. Cytomorphometric assessment was carried out to determine cellular growth modulations in the root apical meristem (RAM) comprised of cell proliferation and transition domains. At 20°C in hydroponics, root apex growth in F. pratensis ‘Dotnuva I’ and ×Fl. braunii ‘Punia DS’ was rather similar, accounting for about 0.9 mm RAM length after 30 days. Further, upon hardening at temperature +8/+2°C (14/14 days) the mean RAM length in ×Fl. braunii exceeded that of F. pratensis by 42%, reaching 1.7 and 1.2 mm, respectively (×Flb>Fp at P < 0.01). Such differences were mostly due to the apparent expansion of the transition domain of the RAM in the hybrid. Also, a specific acclimation feature in the RAM of ×Fl. braunii was revealed, manifesting itself as a sharp RAM cell width increment (×Flb>Fp at P < 0.01). We assume that different RAM growth modulation under lowered temperature results in setting up a different pattern of plant growth in autumn / early winter period, namely, ×Fl. braunii expands its RAM and keeps growing, while F. pratensis declines cellular growth in the RAM and halts its vegetation.
For the first time, we describe the RAM growth in ×Fl. braunii and F. pratensis in detail which could serve as a layout for new methodologies in growth biology studies of perennial grasses.
Key words: cell growth, hardening, perennial grasses, root apical meristem.
Full text: 105_4_str44.pdf