Physiological characters of four lowland chilli varieties (Capsicum annum L.) with root cutting

The root system plays some vital roles in overall plant development, promoting plant anchorage, absorption of nutrients and water, and hormone production. Cutting is an attempt to root regeneration and enhance the plant's metabolism capability, including canopies and roots for high yielding. Non-hybrid chilli can be used as a model plant because Indonesia's chilli yield has not been maximal yet. This research was aimed to determine the physiological characters of four lowland chilli varieties with root cutting. This study was designed using a randomized, complete block design (RCBD) with two factors: root cutting and varieties. The root cutting factor consisted of 4 levels: root cutting in seeding, root cutting in ridging, root cutting in seedling and ridging, and non-cutting. The varieties factor consisted of 4 levels, namely Lembang, Kencana, Tanjung, dan Ungu. The results showed that root cutting in ridging for Kencana, Lembang, and Ungu increased stomatal conductance, transpiration rate, CO2 intercellular, chlorophyll accumulation, photosynthesis rate, and improved fruit yield per plant. However, Tanjung did not respond to root cutting treatment because it did not improve plant physiology characters and fruit yield than non-cutting treatment. It is concluded that root cutting in ridging can be improved plant physiology, which contributes to increasing yield on Kencana, Lembang, and Ungu.

​Effect of Different Media on In vitro Rooting in Different Cultivar of Lilium longiflorum Cv. Elite, Brunello, Cordelia

Background: Lilium (Lilium longiflorum Thunb.) belongs to the family Liliaceae and is a native of Northern Hemisphere (up to South Canada and Siberia). Conventionally Lilium can easily be propagated by sexual and asexual methods of propagation but these prevalent methods are not capable of meeting the increasing demand in domestic and global market. Generally, Lilium is propagated through bulbs but, limited number of bulbs per plant, long dormancy period of bulbs which again results into non-availability of planting material throughout the year. Keeping in view the above facts, the present study was undertaken with the following objective: “To standardize the cost effective protocol for micro propagation of lilium to produce disease free and true to type plants at a faster rate”. Methods: The present investigation was carried out in the Tissue Culture Laboratory of the Centre for Research and Application in Plant Tissue Culture. The experiment was laid out in a C.R.D. (Factorial) with three replications. In vitro raised bulblets were separated out and were transferred on to the root regeneration media. Different levels of NAA were used in MS media for the rooting of in vitro raised bulblets and percent rooting of plantlet is recorded. Result: It was interesting to note that the media LR-3 (MS + NAA 1.0 mg/l) is most efficient for rooting in all type of cultivars. All the three cultivars used responded very poor on media LR-1 (MS basal).

Effects of Polyamines And Silver Thiosulphate On Phoenix Dactylifera L. Cv. Quntar Micropropagation And Molecular Analysis.

There are some limitations in the practical applications of in vitro date palm tissue culture, such as low multiplication efficiency, low rooting rate, and high mortality experienced by in vitro raised plantlets during laboratory to soil transfer. The objective of the present study is to determine the effect of polyamines (putrescine "PUT" and spermidine" SPD") and silver thiosulfate (STS) on enhancing propagation of date palm cv Quntar in vitro. Media supplemented with 75 mg L-1 SPD in combination with 10 mgL-1 STS gave the highest percentage of callus producing buds (83.34%) and average bud formation (16.3) per jar. The addition of PUT and STS to the medium was most effective in root regeneration and the number of roots per shoot, where the best result 91.67% and 6.37 roots per shoot, respectively, were obtained using 75 mgL-1 PUT and 10 mgL-1 STS, resulting in fast-growing plantlets during acclimatization phase, reaching 90% of plant survival. The genetic fidelity assessment of plants derived from micropropagation was confirmed by RAPD analysis. Four operon primers were used, and all of them showed amplified unambiguous (OPA02, OPC-04, OPD-07, and OPE-15). All generated bands were monomorphic and had no variation among the tissue culture-derived plants tested. Accordingly, these results indicate that adding polyamines and silver thiosulfate to the nutrient medium of date palm cv. Quntar is beneficial in improving shoot organogenesis, rooting, and production of genetically stable date palm plants.

Micropropagation and experimental field cultivation of Pulsatilla turczaninovii Kryl. et Serg. (Ranunculaceae)

Pulsatilla turczaninovii is an important medicinal plant, valued for high ornamental value of melliferous flowers. We assessed the efficiency of reproduction under in vitro conditions and the ex situ growth capacity of this important representative of the world flora. The seed germination percentage was assessed, followed by determination of micropropagation rate and rooting efficiency. Then, the possibility of plant development in three consecutive growing seasons was assessed. The in vitro germination percentage was approximately 55%. The highest multiplication coefficient, amounting to 5.17, was obtained on modified MS medium supplemented with 2.5 mg L−1 2iP and 1.0 mg L−1 IAA. Our study provided unique insight on biochemical background of root regeneration in P. turczaninovii. In comparison with standard auxin-supplemented rooting medium, the treatment with 1.0 mg L−1 level of ethylene precursor ACC elevated rooting by about 20%. The total content of soluble sugars was proved to be biomarker of rhizogenesis in the studied species. Their concentration was positively correlated with rooting efficiency, while a level of phenolic was positively correlated with the length of regenerated roots, and their number per rosette. The cultivation of the acclimatized material was successfully carried out and was evaluated over three subsequent years. In the third year of cultivation, the plants entered the stage of generative development and most of them bloomed profusely.

An auxin-mediated ultradian rhythm promotes root regeneration in Arabidopsis

Ultradian rhythms have been proved to be critical for diverse biological processes. However, comprehensive understanding of the short-period rhythms remains limited. Here, we discover that leaf excision triggers a gene expression rhythm with ~ 3-h periodicity, named as the excision ultradian rhythm (UR), which is regulated by the plant hormone auxin. Transcriptome analysis found more than 4,000 excision UR genes which are diverse in terms of biological function. Promoter–luciferase analyses showed that the spatiotemporal patterns of the excision UR were positively associated with de novo root regeneration (DNRR), a post-embryonic developmental process. Genetic studies showed that EXCISION ULTRADIAN RHYTHM 1 (EUR1), which encodes ENHANCER OF ABSCISIC ACID CO-RECEPTOR1 (EAR1), an abscisic acid signaling regulator, was required to generate the excision ultradian rhythm and promote root regeneration. Moreover, the ear1 mutant exhibited the absence of auxin-induced excision UR generation and partial failure to rescue DNRR. These results demonstrate that leaf excision activates EAR1-mediated excision UR and reprograms the expression of a large set of genes involved in DNRR.