Microspore-derived Embryo Formation and Morphological Changes during the Isolated Microspore Culture of Radish (Raphanus sativus L.)

Abstract

Raphanus sativus L. cv. Taebaek, a efficiently microspore-derived embryo (MDE)-forming cultivar, and 'Chungwoon', a non-MDE-forming cultivar were selected as donor plants for isolated microspore culture. Radish flower bud of 2.0 (small, S), 4.0 (medium, M), and 6.0 (large, L) ± 0.5 mm in length were isolated to determine the temporal relationship between flower bud size and MED yield. Anatomical observations revealed no difference in the structure of the flower buds between the two cultivars. In both cultivars, the stigmas were much longer than the floral leaf in M-sized flower buds. The MDE yields for 'Taebaek' per petri dish were 6.6 and 1.3 for M-and L-sized of flower buds, respectively, but MDE formation was not induced in the S flower buds. On the other hand, 'Chungwoon' failed to form MDEs in all flower buds. The microspore density of 'Taebaek' was 1.3 times more than that of 'Chungwoon' for M sized flower buds. Of the M-sized buds from 'Taebaek' and 'Chungwoon', 92.1 and 81.6%, respectively, were in the late uninucleate microspore stage, which is characterized by the highest frequency of MDE formation. Anatomical observations of MDE formation revealed that the microspores were able to divide to form a primordium from which cell division took place continuously in the 'Teabeak' cultivar. However, the microspores of 'Chungwoon' failed to progress beyond the primodium stage, resulting in lack of MDE formation. By contrast, after the formation of the primordium, various developmental stages of embyos from microspore were observed in the 'Taebaek' cultivar. These results can be used to determine MDE forming potentials of radish cultivars.Additional key words: anatomical observation, developmental stage, embryogenesis, flower bud, late uninucleate stage *Corresponding author: somerze@mokpo.ac.kr † These authors contributed equally to this work.※ Received

Induction of embryogenesis in <i>Brassica rapa</i> L. isolated microspore culture

“…В качестве промывочной среды также может быть использована среда ½NLN-13 (Domblides et al, 2016;Shumilina et al, 2020) (Gu et al, 2003), H.Y. Na (Na et al, 2009) и Y. Zhang (Zhang et al, 2012) с соавторами было сообщено об улучшении образования эмбрионов при добавлении активированного угля вместе с агарозой. Использование активированного угля приводит к повышению эффективности эмбриогенеза, формированию, росту и развитию эмбрионов за счет нейтрализации токсичных соединений, продуцируемых старыми и нежизнеспособными микроспорами (Kott et al, 1988;Dias, 2001).…”

Association of bud and anther morphology with developmental stages of the male gametophyte of melon (Cucumis melo L.)

“…As a rule, plant material is se lected based on such markers as the morphological characteristics of the flower buds and anthers (Takahata, Keller, 1991;Parra-Vega et al, 2013). In rape, soya, reddish, tomato, balsam apple, these markers include the length and widths of their flower buds (Weber et al, 2005;Han et al, 2014;Sumarmi et al, 2014;Adhikari, Kang, 2017;Nguyen et al, 2019). Several studies have proved that such parameters as the size and color of the flower cup as well as the cup/corolla length ratio and anther size can do the trick (De Moraes et al, 2008;Parra-Vega et al, 2013;Zhang et al, 2013).…”

Embryogenesis of European Radish (Raphanus sativus L. subsp. sativus Convar. Radicula) in Culture of Isolated Microspores In Vitro

“…Indeed, many statistical data are needed to study the biological mechanisms in order to draw reliable conclusions. In vitro microspore culture of one of the most responsive cultures to embryogenesis, B. napus, has been used to study totipotency [4,10,11], hormone signaling [12][13][14][15][16][17], cell walls [18][19][20][21], and the role of the suspensor in embryoid formation [5,15]. Nevertheless, there are still many unknowns in this field of knowledge, scientists' opinions do not coincide in all aspects, and new evidence and refutations of hypotheses continue to emerge.…”