Plant regeneration from in vitro leaves of four commercial Pyrus species

Abstract

An efficient shoot regeneration from in vitro leaf sections of Pyrus communis Bartlett, P. pyrifolia Shenbuzhi, P. bretschneideri Zaosu and P. ussuriensis Manyuanxiang was successfully developed for use in future transgenic studies. On the basis of regeneration frequency and average shoot numbers, optimal shoot regeneration was obtained on leaf sections of P. communis Bartlett when cultured on Murashige and Skoog complete medium containing 6.0 mg/l BA (6-benzyladenine) and 0.1 mg/l NAA (α-naphthaleneacetic acid), while Quoirin and Lepoivre complete medium supplemented with 1.0 mg/l TDZ [thidiazuron (N-phenyl-N 1 -1,2,3-thiadiazol-5-ylurea)] and 0.1 mg/l NAA was found best for P. pyrifolia Shenbuzhi, and Nitsch and Nitsch complete medium containing 3.0 mg/l TDZ and 0.1 mg/l NAA or 0.2 mg/l IAA was suitable for P. bretschneideri Zaosu or P. ussuriensis Manyuanxiang, respectively. After cutting the leaves into three sections perpendicular to the midrib and culturing under the equivalent conditions, regeneration occurred more frequently on basal sections than middle sections, and no shoots formed on apical sections. A ratio of NH 4 + -N/NO 3 --N of 1:2~1:7 was found beneficial for shoot regeneration. 75.0-87.5% of proliferating shoots formed roots after 4 weeks of transfer to 1/4 strength of Murashige and Skoog complete medium supplemented with 2.5 mg/l IBA (indole-3-butryric acid) and 30.0 g/l sucrose. Regenerated plants were successfully established under greenhouse conditions.

In vitro Propagation of Kainth (Pyrus pashia) Using Explants from Forced Cutting

“…Hu and Wang [25] reported that cytokinins, especially BAP stimulated axillary bud development but at higher concentration shoot elongation was suppressed. Similarly, higher number of shoots per explant during proliferation stage on M2 as compared to M1 has been reported by Hassan [26] in Le Conte pear, [27] in Bartlett pear and [28] on figure due to higher nutrient concentration.…”

<i>In Vitro</i> Propagation and Recovery of Eight Apple and Two Pear Cultivars Held in a Germplasm Bank

“…In vitro micropropagation has been reported in several cultivars of apple [13] and pear trees propagated in vitro [14] [28], but their efficiency depends on genotype and other factors [22]. Other cytokinins such as zeatin, 2iP and kinetin have also been tested in several studies and have generally been found to be less active [28].…”

REGENERASI TUNAS ADVENTIF DARI EKSPLAN DAUN TEMBESU (Fagraea fragrans Roxb.) MELALUI TEKNIK KULTUR JARINGAN

“…Hal ini berarti tunas adventif dari daun tembesu memerlukan konsentrasi nitrat lebih banyak untuk menginduksinya. Penelitian lain menggunakan konsentrasi nitrat yang mencapai tujuh kali dari ammonium digunakan untuk menginduksi tunas adventif dari daun Pyrus pyrifolia (Tang, Luo, & Liu, 2008) Konsentrasi nitrat yang ditingkatkan hingga 100 mmol dapat menurunkan persentase tumbuh eksplan. Tidak hanya ammonium yang bersifat merugikan bagi tanaman (Sen & Batra, 2011;Iranbakhsh, Ebadi, & Zare, 2011), terbukti nitrat dalam jumlah banyak dalam media juga dapat merugikan bagi tanaman khususnya tembesu.…”

“…Hal ini menjelaskan bahwa tunas adventif dari daun tembesu memerlukan konsentrasi nitrat lebih banyak untuk menginduksinya. Induksi tunas adventif dari daun Pyrus pyrifolia memerlukan perbandingan ammonium nitrat mulai dari 1:2 sampai 1:7 (Tang et al, 2008).…”