Enhanced Regeneration Through ex vitro Rooting and Agrobacterium-mediated Genetic Transformation of Eggplant (Solanum melongena L.)

Regeneration of in vitro multiple shoots was achieved through organogenesis on MS supplemented with 2.0 mg/l BAP and 0.5 mg/l Kn from cotyledonary leaf explants of two local varieties of eggplant (Solanum melongena L.). Elongation of regenerated shoots was obtained on growth regulator free MS. In vitro root induction from excised regenerated shoots was less effective on MS with or without plant growth regulators. On the other hand regenerated shoots treated with 10 mM IBA for 5 min were found to be effective for ex vitro rooting in sterilized soil. Following sufficient development of roots, the ex vitro rooted plantlets were acclimatized in growth room condition, and were transferred to the field having 100% survival rate. The regeneration system developed was utilized for Agrobacterium-mediated genetic transformation using Agrobacterium tumefaciens strain LBA4404/pBI121 containing GUS and nptII genes. Adequate transformation response was obtained from cotyledonary leaf segments with bacterial suspension having an optical density of 0.50 at 600 nm with 30 min incubation followed by co-cultivation period of 72 hrs in Nayantara (BARI Begun-5) variety of eggplant. Selection of transformed shoots was carried out on MS supplemented with 2.0 mg/l BAP, 0.5 mg/l Kn, 300 mg/l carbenicillin and 100 mg/l kanamycin. Stable integration of GUS and nptII genes in Nayantara were confirmed through PCR analysis using the genomic DNA isolated from transformed shoots. Plant Tissue Cult. & Biotech. 31(1): 97-108, 2021 (June)

Fluctuation in Germination on Exposure to Salt Stress in Trifolium Alexandrium L. in Cultivars

Trifolium alexandrinum L. is a leguminuous plant having tremendous nutritional values associated with it to be utilized as cattle feed. The germination is affected by different factors and one of them being the water absorption capacity of seeds for initial germination. In our study three cultivars of T. alexandrinum viz. BB1 BB2 BB3 were selected and their corresponding seeds were germinated under Na2SO4 stress. The salt concentration chosen for the study ranged from 0 mM, 25 mM, 50 mM, 75 mM, 100 mM, and 150 mM. The study revealed that the salt concentration 0 mM, 25 mM, 50 mM were not having pronounced effect but upon increasing the salt concentration the rate of germination decreased and hence the radical, plumule and cotyledonary leaf also was drastically reduced

Micropropagation of Two Varieties of Bell pepper (Capsicum annuum L.)

Cotyledonary leaf and node of two varieties, namely red and yellow of Bell pepper (Capsicum annuum L.) were cultured in MS with different concentrations and combinations of plant growth regulators. The cotyledonary leaf was found to be most responsive towards multiple shoot regeneration. The leaf explants of red variety showed best result towards shoot regeneration in MS with BAP (8.0 mg/l), NAA (0.02 mg/l) and IAA (1.0 mg/l). Eighty per cent explants responded within 13 - 14 days, and the mean number of shoot per explant was was found to be 5.67. The cotyledonary leaf explants of yellow variety showed promising result when the cotyledonary leaf explant was cultured in MS with BAP (8.0 mg/l) and NAA (0.5 mg/l) being the mean number of shoot per explants 5.13 and 70% of them responded within 14 - 15 days. Maximum root induction was found in MS with IBA (0.5 mg/l) in both capsicum varieties. After successful root formation plantlets were transplanted and acclimatized to the soil. Plant Tissue Cult. & Biotech. 30(2): 267-275, 2020 (December)

In vitro regeneration of three varieties of Brassica campestris L. grown in Bangladesh

A reproducible in vitro regeneration system was developed for three varieties of Brassica campestris L. namely Agrani, BINA Sarisha-10 and BINA Sarisha-6 using hypocotyl and cotyledonary leaf with petiole as explants. MS medium supplemented with 2.0 mg/l BAP and 0.2 mg/l IAA was found to be the best for the multiple shoot formation for all the three varieties. Among three varieties, BINA Sarisha-6 showed best response in terms of shoot regeneration as well as number of shoots per explant (9.0) using hypocotyls as explants. In case of Agrani and BINA Sarisha-10 highest number of shoot per explants were found 8.2 and 7.0, respectively. Interestingly in vitro regenerated shoots of BINA Sarisha-6 and BINA Sarisha-10 were produced in vitro flowers on shoot regeneration media. Best root induction in BINA Sarisha-6, Agrani and BINA Sarisha-10 was achieved on MS media supplemented with 0.5 mg/l IBA. After proper hardening, the in vitro regenerated plantlets were successfully transplanted into soil. Bangladesh J. Sci. Ind. Res.55(3), 181-188, 2020

Callus induction and regeneration of Alkanna orientalis var. Orientalis and A. sieheana

Callus induction and proliferation of Alkanna orientalis var. orientalis and Alkanna sieheana containing valuable alkannin/shikonin (A/S) derivates were investigated using leaf base and stem segment explants. Stem segments and cotyledonary leaf base of both species were cultured on Murashige and Skoog medium fortified with different concentrations of BAP, Kn, NAA, IAA and IBA for callus induction and shoot regeneration. High frequency reproducible, prolific and compact calli formation was obtained from the stem segments of both species in all media tested. The frequency variations of callus induction and shoot regeneration were discussed in terms of different species, plant growth regulators and explant resources. A. orientalis and A. sieheana may be considered to be alternative plants for the A/S production in vitro.

In vitro regeneration and molecular characterization of some varieties of Lycopersicon esculentum Mill. in Bangladesh

An efficient regeneration protocol was established for two varieties (BARI tomato-9 and BARI tomato-15) of tomato (Lycopersicon esculentum Mill.) using three explants namely cotyledonary node, cotyledonary leaf and hypocotyls. Among the three explants, maximum number of shoots was produced from cotyledonary leaf explants of BARI tomato-15 on MS with 2.0 mg/l BAP and 0.5 mg/l IAA. In this combination of BAP and IAA 86%, on an average, cotyledonary leaf explants showed regeneration response 14.12 shoots/explants. Explants from hypocotyl showed best results in MS medium with 2.0 mg/l BAP and 0.2 mg/l IAA in both the varieties. In case of cotyledonary node, BARI tomato-15 showed 6.0 shoot/explant on MS with 2.0 mg/l BAP and 1.0 mg/l IAA. Molecular characterization of total ten varieties of tomato in Bangladesh was done by using six arbitrary oligonucleotide RAPD primers. A total of 140 bands were produced where the highest genetic distance (0.6769) was found between BARI tomato-3 and Mintoo tomato and lowest distance (0.1035) was observed between BARI tomato-7 and BARI tomato-8. This result will be useful for designing future breeding programs. Bangladesh J. Sci. Ind. Res.54(2), 117-124, 2019

Stress-Triggered Long-Distance Communication Leads to Phenotypic Plasticity: The Case of the Early Root Protoxylem Maturation Induced by Leaf Wounding in Arabidopsis

Root architecture and xylem phenotypic plasticity influence crop productivity by affecting water and nutrient uptake, especially under those environmental stress, which limit water supply or imply excessive water losses. Xylem maturation depends on coordinated events of cell wall lignification and developmental programmed cell death (PCD), which could both be triggered by developmental- and/or stress-driven hydrogen peroxide (H2O2) production. Here, the effect of wounding of the cotyledonary leaf on root protoxylem maturation was explored in Arabidopsis thaliana by analysis under Laser Scanning Confocal Microscope (LSCM). Leaf wounding induced early root protoxylem maturation within 3 days from the injury, as after this time protoxylem position was found closer to the tip. The effect of leaf wounding on protoxylem maturation was independent from root growth or meristem size, that did not change after wounding. A strong H2O2 accumulation was detected in root protoxylem 6 h after leaf wounding. Furthermore, the H2O2 trap N,N1-dimethylthiourea (DMTU) reversed wound-induced early protoxylem maturation, confirming the need for H2O2 production in this signaling pathway.

Germination and growth of ornamental pepper plants due to salinity

Seeds need favorable environmental conditions to germinate but sometimes these conditions are not available. The goal of this work was to evaluate the influence of different concentrations of NaCl on in vitro germination and development of Capsicum annuum seedlings. The experiment was conducted at the Laboratório de Biotecnologia Vegetal at Centro de Ciências Agrárias (CCA) of Universidade Federal da Paraíba (UFPB), Areia, PB, Brazil. Ornamental pepper seeds (Capsicum annuum L.) were submitted to five concentrations of NaCl: 0, 25, 50, 75 and 100 mM. The experimental design was completely randomized, with five treatments and seven replicates, each replicate consisted of one flask with one seed. After 14 days in vitro, the germinated seedlings were characterized for seedling height, hypocotyl width, cotyledon leaf length, cotyledon leaf width, leaf number, radicle length, fresh matter and germination. The data were submitted to analysis of variance by the F test ( p ≤ 0.05). When significant differences were detected, the data were submitted to regression analysis. Percentage of abnormal plantlets was also calculated and submitted to descriptive statistical analysis. The percentage of germination was not affected by the NaCl concentrations used in this work. However 75 e 100 mM salt concentrations influenced the cotyledonary leaf width, total fresh matter and percentage of abnormal seedlings.

Leaf and seedling morphology: the two prospective parameters to trace phylogeny in apiaceae subfamily apioideae.

Determination of phylogenetic affinity among the members of Apiaceae especially the subfamily Apioideae is much debatable. The morphological evidences on inflorescence, fruit and seed characters showed little concomitance with those derived from molecular parameters as far as groupings in clades are concerned. In the present study involving few selected Apiaceae members, a Dendrogram was computed and a putative evolutionary trend was outlined based on leaf margin insertion pattern and cotyledonary leaf features, general plant morphology as well as leaf surface micromorphology by SEM. The members of Apiaceae with broad-ovate pinnatifid to pinnatipartite leaves and ovate –lanceolate cotyledonary leaves were included in a distinct cluster but the members with pinnatisect – decompounds leaves and linear cotyledonary leaves were included in a separate cluster. Long Coriander (Eryngium foetidum) included in the subfamily Saniculoideae may represent the most primitive condition having simple entire leaf with spiny margin. The member like Long coriander might have served as progenitor stock from which Coriander, Celery, Parsley (all with ovate pinnatifid to pinnatipartite leaves) and Cumin, Fennel, Dill (all having pinnatisect to decompounds leaves with linear segments) might have originated as evidenced by gradual increase in marginal insertion. Similarly, gradual narrowing of ovate-lanceolate cotyledonary leaves might have given rise to narrow linear cotyledonary leaves. Leaf-margin insertion pattern and cotyledonary leaf features appeared to be promising in tracing phylogeny in Apiaceae especially in Apioideae. Simple entire leaf represents the primitive condition and evolution in Apiaceae supposed to have progressed towards gradual increase in marginal insertion leading to pinnately dissected, pinnatipartite and ultimately to decompound leaves with narrow linear segments. Dendrogram computed from morphological features showed concomitance with that phylogenetic trend as far as grouping and interrelationships of members are concerned. In the present study leaf margin insertion pattern and seedling morphology appeared to be instrumental in tracing the phylogeny in Apiaceae specially subfamily Apioideae while molecular systematics are not conclusive.