Factors Influencing in Vitro Organogenesis of Chrysanthemum morifolium cv. ‘Resomee Splendid’

Abstract

BackgroundChrysanthemum; also commonly known as mums or chrysanths, is one of the most important ornamental crops worldwide. Introducing desirable traits into this valuable plant by the conventional breeding has so far been faced with some restrictions due to the limited gene pool and cross-incompatibility. Therefore, breeders have decided to exploit Agrobacterium-mediated transformation methods in order to satisfy the growing market demands. However, more efficient in vitro regeneration protocols are required for this approach.ObjectivesThe objective of this research was to develop an efficient protocol for an in vitro plant regeneration by the examining the effects of various combinations and concentrations of the plant growth regulators (PGRs) and different explants types.Materials and MethodsThe leaf and petiole explants of the Chrysanthemum morifolium cv. ‘Resomee Splendid’ were collected from the in vitro grown plantlets. Murashige and Skooge (MS) medium was supplemented with different concentrations and combinations of benzylaminopurine (BAP), 1-naphthaleneacetic acid (NAA) and thidiazuron (TDZ). Thereafter, the effects of these hormonal treatments were investigated on shoot initiation percentage, the average number of shoots per explants, callogenesis, and the type of organogenesis in regard to both types of the explants.ResultsShoots were directly formed from leaf explants on the media that only contained BAP without callus formation. Amongst the other hormonal treatments, a combination of 4.5 mg.L-1 BAP plus 1 mg.L-1 NAA resulted in the direct organogenesis from the leaf explants, which was superior to the other combinations and concentrations. In regard to the petiole explants, direct shoot formation occurred in all the media except for the ones which were fortified with TDZ. In this case, considering the shoot initiation percentage and the mean shoot number per explants, the best results were achieved in the medium supplemented with 1.5 mg.L-1 BAP and 1 mg.L-1 NAA. Results showed that interaction of either BAP or TDZ with NAA was necessary for the callus induction.ConclusionsSignificant differences in shoot initiation percentage and the average number of shoots per explants were observed both in leaves and petioles grown on different media. Moreover, the callogenesis rates, as well as organogenesis types, showed some differences among the studied explants when compared on the same media.

Development of an Efficient In vitro Regeneration Protocol for Chrysanthemum (Chrysanthemum morifolium Ramat)

“…1). Similar findings were obtained in several studies using the identical groups of hormones (Xu et al 2012, Naing et al 2014, Kazeroonian et al 2018.…”

“…Addition of cytokinin in the regeneration medium generally increases shoot number per explant. Several previous reports have confirmed that BAP accelerates the development of the shoot buds as well as enhancing the shoot primordial development in chrysanthemum and in other plants (Lee et al 1997, Yesmin et al 2014, Kazeroonian et al 2018). Among the nine treatments tested T6 produced highest mean number of shoot/explant 8.67 and 7.67 for Y and BARI Chry-2 variety, respectively.…”

“…In vitro regeneration of chrysanthemum was found to be highly influenced by the interaction of PGRs, plant genotype and explants type (Lim et al 2012, Teixeira et al 2015. Most of the studies revealed direct/indirect organogenesis/embryogenesis of C. morifolium in MS medium using different concentrations of auxins (NAA, IAA, 2, 4-D) along with that of cytokinins (BAP, BA and TDZ) (Lim et al 2012, Huang et al 2018, Kazeroonian et al 2018. Present study revealed that the addition of (0.5 mg/l) IAA in MS media induced regeneration responses in leaf explants and a significant increase in regeneration percentage were recorded (from 37.5 to 76% for yellow flowered variety and 35.7 to 70% for BARI Chry-2 variety) up to the application of 1 mg/l IAA.…”

In vitro Regeneration of Solanecio biafrae Through Direct Shoot Organogenesis

“…11 However, shoots were formed directly in the leaf explants of Chrysanthemum morifolium on the media supplemented with BAP. 18 In contrast, leaf segments of S. viarum did not induce any shoot with BA. 11 Adventitious shoots were also obtained in Titanotrichum oldhamii using medium supplemented with 0.1mg/L BA.…”

CHỌN LỌC IN VITRO MỘT SỐ DÒNG CÚC ĐẠI ĐÓA (Chrysanthemum × morifolium) CHỊU MẶN

“…Theo nghiên cứu trước đây, tái sinh chồi bất định từ mẫu lá thường được thực hiện bằng cách bổ sung auxin kết hợp với cytokinin, cụ thể nồng độ auxin cao hơn so cytokinin, sẽ tốt cho quá trình tái sinh chồi. Theo Kazeroonian et al (2018), sử dụng 4,5 mg/l BAP kết hợp 1,0 mg/l NAA, chồi được tái sinh trực tiếp từ mảnh lá, cho số chồi trung bình/mẫu đạt 2,06 chồi/mẫu sau 7 tuần [15], trong khi nghiên cứu của chúng tôi cho thấy, môi trường tái sinh chồi trực tiếp từ lá khá đơn giản, chỉ cần bổ sung BAP 0,50 mg/l, chồi được tái sinh trực tiếp từ mảnh lá sau 5 tuần và cao hơn.…”