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The development of calyxes in ‘Korla’ fragrant pear is influenced by hormones. This study was conducted to investigate the effects of different plant growth regulators on the endogenous hormone content of young ‘Korla’ fragrant pear fruit. The hormone contents [indoleacetic acid (IAA), gibberellin acid (GA₃), and abscisic acid (ABA)] of young ‘Korla’ pear fruits treated with water, IAA, and triiodobenzoic acid (TIBA) were determined by high-performance liquid chromatography, and the relationship between the content and ratio of endogenous hormones and calyx abscission in ‘Korla’ fragrant pear was explored. The results showed that the rate of calyx abscission in the ‘Korla’ pear fruits treated with TIBA was significantly higher than that of fruits treated with water and IAA, and that of fruits treated with water was significantly higher than that of fruits treated with IAA. The GA₃ content was higher than the IAA and ABA contents during each period. The IAA content of the stalk was higher than that of the calyx tube and flesh. The GA₃ and ABA contents of the calyx tube were higher than those of the stalk and flesh. The IAA and GA₃ contents of the first order were higher than those of the fourth order. The ABA content of the fourth-order fruit was higher than that of the first order. The (IAA+GA₃)/ABA in the calyx tube was significantly higher than that in the flesh and fruit stalk. After IAA treatment, the IAA, GA₃, and ABA contents of the first-order calyx tube increased by 47.7%, 17%, and 31.6%, respectively, whereas those of the fourth-order calyx tube increased by 65.3%, 39.9%, and 33.2%, respectively. After TIBA treatment, the IAA, GA₃, and ABA contents of the first-order calyx tube increased by 46.1%, 36.5%, and 50.0%, respectively, the IAA content of the fourth-order tube decreased by 25.5%, and the GA₃ and ABA contents increased by 22.0% and 12.2%, respectively. The IAA, GA₃, and ABA contents of the flesh and fruit stalk did not significantly differ from those in the calyx tube. The results indicated that spraying IAA during flowering promoted calyx persistence, whereas spraying TIBA promoted calyx abscission. These findings provide certain theoretical references and practical criteria for improving the quality of ‘Korla’ fragrant pear.

Syngonium podophyllum ‘White Butterfly’, one of the most popular ornamental foliage plants, is propagated almost exclusively through in vitro shoot culture. Ex vitro rooting, however, has been associated with severe Myrothecium leaf spot (Myrothecium roridum Tode ex Fr.). The objective of this study was to establish a method for regenerating well-rooted plantlets before ex vitro transplanting. Leaf and petiole explants were cultured on a Murashige and Skoog (MS) basal medium supplemented with N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU), N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (TDZ), 6-benzyladenine (BA), or N-isopentenylaminopurine (2iP) with α-naphthalene acetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D), respectively. Calli formed from leaf explants cultured on the basal medium supplemented with CPPU or TDZ with 2,4-D or with NAA as well as from petiole explants cultured on the medium supplemented with BA, CPPU, or TDZ with 2,4-D or NAA. The calli, however, failed to differentiate, and shoot organogenesis did not occur. Culture of nodal explants on the MS basal medium supplemented with 9.84 μm 2iP, 8.88 μm BA, 8.07 μm CPPU, or 9.08 μm TDZ with 2.26 μm 2,4-D resulted in the formation of protocorm-like bodies, adventitious shoots, and subsequently well-rooted plantlets. MS basal medium supplemented with 19.68 μm 2iP and 1.07 μm NAA resulted in the highest percentage (92.9%) of nodal explants producing protocorm-like bodies and an average of 16.9 well-rooted plantlets per nodal explant. Adventitious shoots were able to root in the initial induction medium, but better root development occurred after shoots with protocorm-like bodies were transferred onto MS basal medium supplemented with 9.84 μm 2iP and 2.69 μm NAA. Regenerated plantlets were stable and grew vigorously with 100% survival rates after ex vitro transplanting to a container substrate in a shaded greenhouse.

Chlorophytum amaniense Engl. ‘Fire Flash’ is a popular exotic ornamental foliage plant as a result of its unique coral-colored midribs and petioles and tolerance to interior low light levels. Currently, demand for propagative materials exceeds the availability of seeds. This study was intended to develop an in vitro culture method for rapid propagation of this cultivar. Leaf and sprouted seed explants were cultured on a Murashige and Skoog basal medium supplemented with different cytokinins with 1.1 μM α-naphthalene acetic acid (NAA) or 2.3 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Leaf explants showed poor responses in callus production and no adventitious shoots were obtained. Callus formation frequencies from sprouted seeds were 71% and 85% when induced by 9.8 μM N₆-(2-isopentyl) adenine (2iP) with 1.1 μM NAA and 9.1 μM N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (TDZ) with 1.1 μM NAA, respectively. Adventitious shoots occurred after the induced calluses were subcultured on the same concentrations of TDZ or 2iP with NAA. Shoot formation frequencies from calluses cultured on TDZ with NAA and 2iP with NAA were 92% and 85%, and the corresponding mean shoot numbers were 37 and 31 per piece of callus (1 cm³), respectively. Adventitious shoots rooted at 100% after transferring to the basal medium containing 4.4 μM 6-benzylaminopurine (BA) with 2.7 μM NAA. Plantlets, after transplanting to a soilless substrate were easily acclimatized in a shaded greenhouse under a photosynthetic photon flux (PPF) density of 200 μmol·m⁻²·s⁻¹. Regenerated plants grew vigorously without undesirable basal branching or distorted leaves. This newly established regeneration method can provide the foliage plant industry with a means for rapidly propagating ‘Fire Flash’ liners in a year-round fashion.

To select resistant germplasm resources and understand the growth and physiological responses of kiwifruit (Actinidia sp.) to drought stress, five species, Actinidia macrosperma (Acma), Actinidia longicarpa (Aclo), Actinidia deliciosa (Acde), Actinidia hemsleyana (Ache), and Actinidia valvata (Acva), were assessed under tissue culture conditions. Rootless seedlings of five species were cultured in a medium containing polyethylene glycol [PEG (formula weight 8000)] to induce drought stress (0%, 5%, 10%, 15%, and 20%). After a 30-day culture, three growth indices [fresh weight (FW), plant height (PLH), and leaf number (LN)] and six physiological indices were determined, and the drought damage index (DDI) was determined. The DDIs of five species increased, and three growth indices decreased with increasing PEG concentrations. The following changes were observed under 20% PEG treatment conditions: superoxide dismutase (SOD) activities increased significantly in Acma, Aclo, and Ache specimens; peroxidase (POX) activities remained stable in Acde, Ache, and Acva specimens; and catalase (CAT) activities increased sharply in Acma and Acva. Furthermore, the results indicated that soluble sugar (SS) content increased slightly in Acma, Aclo, Acde, and Ache but it decreased in Acva specimens. Proline (PRO) content increased significantly in Acma and Acva, and malondialdehyde (MDA) contents tended to increase under drought stress in all five species. Principal component analysis (PCA) results indicated that the order of drought tolerance in the five genotypes examined in this study under tissue culture conditions was as follows: Acma > Acva > Acde > Aclo > Ache. Therefore, we concluded that Acma and Acva are more resilient germplasm resources that represent promising kiwifruit-breeding materials. Furthermore, tolerance to drought stress in these species should be further investigated under orchard conditions.

This study established a new method for regenerating Anthurium andraeanum Lind. and evaluated effects of different wavelengths from light-emitting diodes (LEDs) on rooting and growth of adventitious shoots. Callus occurred in leaf explants of A. andraeanum ‘Alabama’ and ‘Sierra’ cultured on a modified Murashige and Skoog (MS) basal medium supplemented with four concentrations of N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (TDZ). Adventitious shoots were induced from callus pieces (≈1 cm³) cultured on the modified MS medium containing 6-benzyladenine (BA) with kinetin (KN), BA, and/or KN with 3-indolebutyric acid (IBA) or α-naphthalene acetic acid (NAA). Results showed that 1.82 μM TDZ induced 83.3% and 77.8% of leaf explants of ‘Alabama’ and ‘Sierra’ to produce callus and 24.9 and 24.7 adventitious shoots were produced per callus piece of ‘Alabama’ and ‘Sierra’ cultured on the modified MS medium containing 0.89 μM BA, 2.32 μM KN, and 0.98 μM IBA, respectively. Adventitious shoots were cut and rooted in the modified MS medium containing 0.98 μM IBA and grown under the same light level but with different light qualities. All adventitious shoots rooted; root numbers, root lengths, root fresh and dry weights, and leaf area of plantlets grown under red plus blue light were comparable to those grown under conventional fluorescent white light. Shoot height was the greatest in monochromic blue light followed by red light. Shoot fresh and dry weights of plantlets grown under red plus blue light, however, were significantly greater than those grown under the other light qualities. Plantlets grown under red plus blue light had 22.7% greater total dry weight and more balanced root-to-shoot ratio than those grown under fluorescent white light. These results suggested the use of complex of red plus blue LED could be an option for improving growth of A. andraeanum plantlets in vitro.