In situ seed development and in vitro regeneration of three difficult-to-propagate Lepidosperma species (Cyperaceae)

Field studies of fruit production from Lepidosperma concavum R.Br., L. laterale R.Br. and L. longitudinale Labill. showed that large proportions (21-77%) of fruits were unfilled and that filled and unfilled fruits looked alike. Bagging of inflorescences demonstrated that filled fruits tended to be shed, while empty fruits remained within the inflorescence. Time of collection was critical for obtaining viable seeds, with successful harvesting limited to a short period (weeks) after maturation. The timing of flowering and fruit maturation were fairly consistent between species, populations and years in our study area. In L. concavum fruit production was increased in cultivation compared with wild populations. In all three species, very little or no germination of fruits occurred under nursery conditions. In vitro culture initiation was attempted using intact fruits, nicked fruits and seeds on 1/2MS (Murashige and Skoog) medium with 1 μM zeatin and 0.5M gibberellic acid in darkness. Culture of intact fruit resulted in no germination, while nicked fruit showed some germination response. Best results were achieved from seeds with germination occurring as early as 7 to 18 days depending on the species. Germination of L. concavum, L. laterale and L. longitudinale was 86%, 64% and 83% respectively within 5 weeks. Germination response was strongly influenced by seed maturity. Mature seeds germinated significantly faster than immature seeds. On a small proportion of cultured seeds, calli formed and differentiated into numerous plantlets on growth regulator-free medium. Given the promising results observed in this study, in vitro culture appears to be a practical means of mass propagating Lepidosperma species

Database of cultivated fleshy fruits

Database was created from the Mansfeld's Encyclopedia of Agricultural and Horticultural crops and integrated with variables on: 1) life form of the species, according to the Raunkiær system for plant classification, and 2)Google Scholar research results between 1998 and 2018 for the specie

Large-scale micropropagation of the Australian key species Gahnia radula (Cyperaceae) and its return to revegetation sites

We report on the successful propagation of the sedge Gahnia radula (R.Br.) Benth. from seed by using plant tissue culture, and its successful establishment in the field. This keystone species, although common along parts of the eastern coast of Australia, is currently not available for revegetation because of a lack of efficient propagation methods, leading to the use of substitute species in many restoration programs. Even though seed quality is a common problem for G. radula, one population bearing filled seed was located in the near-east of Melbourne and after harvest of fruit in December 2011, seeds were successfully germinated in vitro after removal of the pericarp. Overnight soaking in sterile 10% (v/v) smoke water before culturing enhanced in vitro germination from 29.2% to 66.7%. In vitro-grown seedlings were then used as starting material for tissue-culture propagation via shoot culture. A micropropagation rate of about six new plantlets per cycle was achieved within 5-6 weeks with liquid half-strength Murashige-Skoog medium and a pulse treatment with 10 M 6-benzylaminopurine (BAP) and 2 M naphthalene acetic acid (NAA). Plants rooted after receiving a pulse treatment with 5 M kinetin and were successfully acclimatised into potting mix and were ready for field planting after 5-6 months. Tube stock was planted into two field sites with minimal weed control. Survival was 98% in both cases 1 month after planting and 54% and 74% after the summer. Division of in vitro-derived plants in the nursery was very successful, with 93-96% establishment of divisions. This research highlights the important role of plant tissue culture in conserving biodiversity of native flora

Development of an in vitro protocol for a difficult-to-propagate endemic Australian dryland sedge species Mesomelaena pseudostygia (Cyperaceae)

In vitro propagation for Mesomelaena pseudostygia a difficult-to-propagate dryland sedge species (Cyperaceae) endemic to Western Australia is described. Multiple avenues to in vitro propagation were investigated: shoot culture, organogenesis and somatic embryogenesis, with zygotic embryos as initiation material. The highest multiplication rate for shoots was 3.4 ± 1.0 after 6 wk on basal medium (1/2 strength Murashige and Skoog) with 2.5 μM kinetin and 0.5 μM 6-benzylaminopurine. Shoots achieved peak rooting (83%) following a pulse treatment on basal medium containing 10 μM indolebutyric acid and 2 μM α-naphthaleneacetic acid for 7 wk, followed by transfer to medium (without growth regulators) for a further 7 wk. Alternatively, in vitro grown shoots were pulse treated on basal medium with both 100 μM indolebutyric acid and 20 μM α-naphthaleneacetic acid for 1 wk then placed in Rockwool plugs (under propagation house conditions) for another 7 wk resulting in 63% root induction. Rooted plantlets were also successfully transferred to potting mixture either in Rockwool plugs or bare rooted and maintained in propagation house conditions with ≥95% survival after 7 wk. These results indicate that micropropagation of M. pseudostygia is feasible for small to medium scale restoration purposes. The highest frequency of callus induction was from cultured zygotic embryos on basal medium with 5 μM α-naphthaleneacetic acid, whereas 2,4-dichlorophenoxacetic acid (2 or 5 μM) produced the largest callus sizes. A low frequency of shoot regeneration occurred in zygotic callus tissues in basal medium treatments containing cytokinin (kinetin or thidiazuron at 1 μM). A small proportion (<20%) of zygotic embryo callus explants from 2,4-dichlorophenoxyacetic acid treatments were found to be embryogenic, firstly developing embryo-like structures after 2 wk on basal medium (minus plant growth hormones), that continued to develop with approximately one in twenty germinating after a further 4 wk on basal medium to form small plantlets. Further optimisation is needed to improve somatic embryogenesis efficiency for mass propagation

Effect of spikelet position on rice anther culture efficiency

Abstract The potential of anthers from different parts of the panicle to induce callus was investigated with the japonica rice variety Taipei 309. The results showed that the callusing abilities of anthers from different spikelet positions were significantly different. After plating 4483, 4496, 4348 anthers from the basal, middle and top parts, the percentage of anthers forming calli was 20% in the basal part, 12% in the middle part and 8% in the top part. The anthers of basal parts containing pollen at all uninucleate stages, including early, middle and late, showed higher callus induction frequency than those from middle and top parts. The green plantlet regeneration frequencies of top, middle and basal spikelets were around 18% in all three cases. From the results it would appear that anthers from the basal part of the panicle should be used in anther culture of rice in order to obtain higher efficiencies, and thereby optimise the usefulness of this technique in rice breeding programmes

Back to the roots: protocol for the photoautotrophic micropropagation of medicinal Cannabis

The aim of this protocol was to develop an alternative in vitro propagation system for Cannabis sativa L. by mimicking nursery-based vegetative propagation. Photoautotrophic micropropagation (PAM) was achieved on rockwool blocks as substrate combined with commercially available fertilizer suitable for cannabis cultivation. Stock plants were initiated after sterilisation in forced-ventilated glass jars which then provided a continuous supply of shoot tip and nodal cuttings. A 97.5% rooting rate of in vitro shoot tip cuttings and successful acclimatisation were achieved within 3 weeks in glass vessels with passive ventilation.© The Author(s) 201