Microshoots of four hazelnut genotypes grown in vitro on Nas and Read medium (NRM) containing various combinations of CuSO4 • 5H2O and myo-inositol were successfully rooted and acclimatized ex vitro without any need of in vitro hardening treatments. Dipping of shoot bases in 1000 ppm indole-3-butyric acid (IBA) solution for 5 or 10 seconds followed by placement of shoots in plant growth regulator free NRM gave rise to formation of roots as early as 8 days. Shoots treated for 5 and 10 seconds rooted similarly, and depending on genotype, 88% to 98% rooting was observed within 15 days after treatment with IBA. Ex vitro survival of shoots three months after in vitro-root induction was 73% when shoots were treated with IBA for 5 seconds and 66% when shoots were treated for 10 seconds. The highest ex vitro survival rate (97%) 3 months after root induction was observed when shoots were treated with IBA solution for 10 seconds, and then cultured directly in peat pellets. Shoots developed good roots, and grew up to 70 cm in height 3 months after root induction. The potential use of rooting and acclimatization protocol for commercial micropropagation of hazelnut is presented.
Mehmet Nuri Nas and Paul E. Read
Mehmet Nuri Nas, Nedim Mutlu, and Paul E. Read
RAPD and phenotypic analysis were conducted to assess clonal stability of hazelnuts generated from axillary buds cultured in vitro for long-term. The nuts produced on in vitro-propagated plants were indistinguishable from those of donor plants. With the exception of rare horizontal (plagiotropic) growth, all in vitro-propagated plants exhibited phenotypes similar to those of donor plants. RAPD analysis did not reveal any somaclonal variation between donor plants from which in vitro cultures were initiated and micropropagated plants (6-year cultures), and no somaclonal variation was detected among in vitro-propagated plants. However, polymorphism (15.6%) was detected between the parent plant and its in vitro-propagated progenies (from seedlings). These results show a good discriminatory power of RAPD to detect polymorphism between samples where it is expected, and it can be effectively used for genetic assessment of micropropagated hazelnut. No evidence of genetic or epigenetic changes was observed in long-term cultured hazelnut, and thus long-term in vitro culture of hazelnut does not seem to limit its clonal propagation.
Ahmet Korkmaz, Mehmet Nuri Nas, Nusret Ozbay, and Iskender Tiryaki
The effects of stratification and priming on germination and emergence performance of narrowleafed purple coneflower (Echinacea angustifolia) seeds were investigated. Seeds were pre-chilled for 3 weeks at 4 ± 0.5 °C (39.2 ± 0.9 °F) in light or primed for 3 days at 20 ± 0.5 °C (68.0 ± 0.9 °F) in darkness in Nas and Read medium (NRM) or in 2% potassium nitrate (KNO3) supplemented with 3 or 5 μm 1-aminocyclopropane carboxylic acid (ACC) or 500 mg·L-1 (ppm) or 1000 mg·L-1 gibberellic acid (GA3). Following stratification and priming, seeds were subjected to germination and emergence tests at 25 ± 0.5 °C (77.0 ± 0.9 °F). Priming the seeds in NRM or KNO3 containing 3 μm ACC gave the highest germination percentages with 78% and 80%, respectively. Stratification alone increased germination to 69% compared to nontreated seeds, which had the lowest germination percentage of 57%. Emergence was enhanced by priming seeds in the presence of 3 μm ACC (75%) compared to stratified seeds (62%), while nontreated seeds had the lowest emergence percentage of 26%. These results indicate that priming in the presence of ACC might be an alternative to lengthy stratification treatments to break the dormancy and improve the germination and emergence of narrow-leafed purple coneflower seeds.