Anatomical and Histological Studies of Grafted Tomato with Interspecific Solanaceous Rootstocks

A study was carried out at the Department of Vegetable Science, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu,India during 2019-2020 to assess the anatomical and histological changes within the graft union of tomato and identify compatible rootstocks for improved propagation of the crop. This experiment involved rootstocks of three wild tomatoes including Solanum torvum, S. sisymbrifolium and S. capsicoides and scions of two tomato hybrids including TNAU tomato hybrid CO3 and Shivam. The grafting was done using the cleft grafting method. The anatomical and histological sections of six graft combinations and two tomato scion samples were viewed microscopically at 7, 14 and 21 days after grafting (DAG). Among the six tomato graft combinations, S. torvum rootstock showed complete development of vascular connection at 21 DAG followed by S. sisymbrifolium rootstock, whereas S. capsicoides rootstock showed only callus growth at 14 DAG. Scion growth dominated the rootstock growth in S. torvum rootstock leading to mismatch of scion-rootstock stem thickness and delayed epinasty symptom at the later stages of plant growth. Of the rootstocks of the three species studied, S. sisymbrifolium rootstock was compatible for tomato grafting though it exhibited delayed vascular connection between the scion and rootstock.

Evaluation of the effects of 5-fluorouracil and cyclophosphamide on Lathyrus sativus L.

Background The effect of 5-fluorouracil (5FU) and cyclophosphamide (CP) on grass pea (Lathyrus sativus L.) has been studied. Results The effect of the selected drugs on radicle length, colchicine induces polyploidy and in vitro callus growth has been studied (concentration used: 5-Fluorouracil—0.01, 0.1, 1 and 10 mM; Cyclophosphamide—1, 10, 20 and 30 mM). The biochemical studies on superoxide dismutase, catalase and lipid peroxidase activity also studied. Radicle length, polyploidy percentage and callus growth decrease in both the drugs in a dose-dependent manner. The SOD, catalase and LP activity decrease with the increase in drug concentration except for low dose (for 5FU—0.01 mM and 1 mM for CP). Induced polyploidy (Control B) than water germinated seedling (Control A) shows higher enzyme activity but a decrease in the increased dose of drugs. Conclusions The present work has been done to assess the effective potentiality of two anticancerous drugs 5FU and CP with an objective to establish plant system as a model for preliminary screening of anticancerous lead compounds. The result of the present work would pave the way for the screening of unknown lead compounds with the potentiality to act as base analogue and DNA cross-linking drugs. This system is faster, cost-effective and convenient than animal model.

Repression of Carotenoid Accumulation by Nitrogen and NH4+ Supply in Carrot Callus Cells In Vitro

The effect of mineral nutrition on the accumulation of the main health beneficial compounds in carrots, the carotenoid pigments, remains ambiguous; here, a model-based approach was applied to reveal which compounds are responsible for the variation in carotenoid content in carrot cells in vitro. For this purpose, carotenoid-rich callus was cultured on either BI (modified Gamborg B5) or R (modified Murashige and Skoog MS) mineral media or on modified media obtained by exchanging compounds between BI and R. Callus growing on the BI medium had abundant carotene crystals in the cells and a dark orange color in contrast to pale orange callus with sparse crystals on the R medium. The carotenoid content, determined by HPLC and spectrophotometrically after two months of culture, was 5.3 higher on the BI medium. The replacement of media components revealed that only the N concentration and the NO3:NH4 ratio affected carotenoid accumulation. Either the increase of N amount above 27 mM or decrease of NO3:NH4 ratio below 12 resulted in the repression of carotenoid accumulation. An adverse effect of the increased NH4+ level on callus growth was additionally found. Somatic embryos were formed regardless of the level of N supplied. Changes to other media components, i.e., macroelements other than N, microelements, vitamins, growth regulators, and sucrose had no effect on callus growth and carotenoid accumulation. The results obtained from this model system expand the range of factors, such as N availability, composition of N salts, and ratio of nitrate to ammonium N form, that may affect the regulation of carotenoid metabolism.

Identification of miR397a and Its Functional Characterization in Callus Growth and Development by Regulating Its Target in Liriodendron

Callus growth and development, a crucial process in plant propagation, is involved in hormonal balance and abundant gene regulation. MiRNAs are key regulators in the process of cell differentiation and development. MiR397 was identified as participating in plant growth, development, and response to stress, and it was regulated by targeting the LAC gene. The regulatory function of miR397 during callus growth and development was not clear in Liriodendron. In this study, LhmiR397a and its targets were identified, and its regulatory function between LhmiR397a and LhLAC11 was shown using qRT-PCR and transient expression in protoplasts. Furthermore, to clarify the regulatory function of LhmiR397a-LhLAC11, transgenic calli overexpressing LhMIR397a, LhLAC11, and mLhLAC11 were separately obtained by Agrobacterium-mediated transfer. The results showed that overexpressing LhMIR397a might retard callus proliferation, while overexpressing LhLAC11 or mLhLAC11 could promote callus proliferation. Genes associated with the cell cycle had decreased expression when LhMIR397a was overexpressed, while increased expression was observed when LhLAC11 or mLhLAC11 was overexpressed. Additionally, the calli overexpressed with LhMIR397a could generate early cotyledons 21 days after induction, and the somatic embryo induction time was short compared with other genotypes. This study identified LhmiR397a and its targets and provided a functional characterization of LhmiR397a in callus growth and development by regulating its target in Liriodendron.

6-BENZYLAMINOPURINE AND 2, 4-DICHLOROPHENOXYACETIC ACID EFFECT ON CALLUS GENESIS OF Brosimum alicastrum

Brosimum alicastrum seeds contain a high percentage of protein and essential amino acids that contribute to a proper nutrition. This tree is an alternative in the so-called crusade against hunger and its management does not involve the use of agrochemicals. The objective of this research was to evaluate the morphogenic response of foliar explants with two growth regulators, 6-Benzylaminopurine (BAP) and 2,4-Dichlorophenoxyacetic Acid (2,4-D) in the induction of calli. Results demonstrated that the combination of 1.5 mg L-1 BAP and 1 mg L-1 2,4-D (TM) and 1.5 mg L-1 BAP with 2 mg L-1 2,4-D (TN) favored callus growth in 100% of foliar explants. Calli were grown in a period of 20 d, in a culture room at 25 ± 4 °C, with 16 h of illumination. Under these conditions, calli remained in slow growth for four weeks. Those explants that generated callus were sub-cultured in fresh medium without activated charcoal. In TM and TN treatments, the multiplication of the cell mass was favored; in TN globular structures were formed. However, explants the same treatments TM and TN with activated charcoal, and under ambient 29 ± 4 °C conditions increased callus growth, but became friable at two weeks. Thus, TM and TN were the better treatments, but activated charcoal was determined to have a negative effect on callus growth.

Pengaruh Komposisi 2,4-D dan BAP Terhadap Pembentukan Kalus Eksplan Pucuk Nilam (Pogostemon Cablin Benth.) secara In Vitro dengan Pemotongan Horizontal dan Vertikal

This study aims to determine the effect of 2,4-Diclorophenoxy Acetic Acid (2,4-D) and Benzyl Amino Purin (BAP) on the formation of callus of patchouli (Pogostemon cablin Benth.) shoot explants by horizontal and vertical cutting methods. The parameters that observed in this study were the percentage growth of callus, time appearance of callus, weight of callus and the morphology of callus. The results showed that horizontal cutting method was able to induce callus growth with the percentages growth of callus were 18,75%, with the time appearance of callus was at 16 days at P1; P10; P12; P13 dan P14. The highest weight of callus obtained was 0.19 grams at P8. The results also showed that the callus yielded had a yellow and cream color, with a compact and crumb textures. Meanwhile, the vertical cutting method was able to induce callus formation with the percentage growth of callus were 12,5%. The fastest time of callus appearance was obtained in P6 and P8, which was 12 day after planting with the highest weight of callus obtained was 0.05 grams at P12. The results also showed that vertical cutting method had brown and dark-brown of callus with a compact and crumb textures.