Development of Nolana carnosa micropropagation protocol

Abstract

Nolana carnosa (Lindl.) Miers ex Dunal, (Fam.: Solanaceae), is a bushy plant native from Chile's north coast. It grows in the Atacama Desert in salty soils under extremely dry conditions. This understudied species is an interesting new ornamental option because of its morphological characteristics like abundant white to deep blue flowering, evergreen foliage and compact growth. With the aim to develop an efficient in vitro culture protocol for this species, during autumn 2015 shoots were collected in Bahia Inglesa, Atacama Region, Chile. Materials were surface sterilized and then initiated to in vitro culture in the lab. Multiplication and rooting trials were done during 2016 once the materials were finally free from fungi and bacteria by surface sterilization and subculture. The multiplication trial used five MS based medium where only BAP content varied (treatments were: 0.0, 0.5, 1.0, 1.5 and 2.0 mg L-1 of BAP). Under the flow cabin 50 plants composed by 3-4 nodes were established. Growth measurements were taken after a 5-weeks cycle. Number of sprouts, multiplication rate, plant's height, fresh and dry weight were measured and water content (%) was calculated. A second trial to enhance rooting was carried out, using 5 MS based media with different contents of IBA in which 50 plants were established. The trial was measured once a week for three weeks counting the number of rooted plants per media. The highest multiplication rate (3.26) and plant size (56.03 mm) were obtained in hormone free media. No statistical difference was observed in plant's weight. Plants grown in 1.5 and 2.0 mg L-1 BAP showed higher dry matter production. Similar results were obtained in rooting experiments where hormone free media enhanced root production in plants (84 and 87%). Finally, both hormone free media used in trials showed the best results.