Nutrient Media Optimization for Date Palm Micropropagation (Phoenix dactylifera L.)

An experimental study was conducted to optimise nutritional media for date palm (Phoenix dactylifera L.) micropropagation by employing a shoot tip as an explant on basic Murashige and Skoog (MS) medium with varied Auxin (IAA, NAA) and Cytokinin (Kinetin and 2ip) concentrations for shoot and root multiplication. The findings of date palm regeneration on basal MS medium (Control) without Kinetin and IAA indicated a decreased survival rate (5.0%) and no root or shoot up to the end of the experiment. When the basal MS medium having different Kinetin and IAA concentrations showed an increased rate of survival, i.e. basal MS +0.5 mg/L of Kinetin and 0.0 IAA (8.0%), MS basal+1.0 mg/L of Kinetin and 0.5 IAA (6.6) and basal MS +2.0 mg/L of Kinetin and 1.5 IAA (7.0) and basal MS contains 1.5 mg/L of Kinetin and 1.0 IAA resulted in highest survival rate (8.8%). However, the highest number of shoots (2.2) and a maximum length of shoots (8.8 cm) were recorded on basal MS medium containing 2.0 mg/L of Kinetin and 1.5 IAA. Moreover, the highest number of roots (3.34) and measured the maximum length of roots (3.56 cm) was achieved on basal MS media containing 1.0 NAA and 1.5 mg/L of 2ip.

In vitro Propagation of Banana (Musa paradisiaca L.) Plant Using Shoot Tip Explant

Banana is a fruit crop which has high demand in Ethiopia, but its production is constrained by lack of disease free planting material with conventional propagation methods. For shoot initiation, shoot tip explants were cultured on MS medium supplemented with 0.5, 1.0, 1.5 and 2.0 mg/L BAP. Similarly, MS medium supplemented with BAP at 1.0, 1.5, 2.0 mg/L in combination with IBA at 0.25 and 0.50 mg/L were used for shoot multiplication. Half- strength MS medium augmented with IBA at 1.0, 2.0, 3.0 and 4.0 mg/l were used for root induction. MS medium without PGRs were used as controls. Finally, hardening of the in vitro derived plantlets was carried out in green house both in the primary and secondary acclimatization stages. Results showed that the highest shoot initiation percent (93.40%), highest mean number of shoots per explant (4.67) and lesser day for shoot induction (11.00) were observed in explant cultured on MS + 1.0 mg/L BAP. With shoot multiplication, highest shooting percent (92.60%), maximum number of shoots (7.67) and highest shoot length (5.27 cm) were recorded on MS + 1.5 mg/L BAP + 0.5 mg/L IBA. The highest rooting percent (93.40%), maximum root number per shoot (7.67) and highest root length (11.00 cm) were found on a half strength MS medium + 2.0 mg/L IBA. The survival rate of plantlets were 96.00% in coco peat substrate in primary acclimatization and 97.92% in forest soil, sand and manure substrates mixed at 3:2:1 ratio in secondary acclimatization. Overall, the result showed that the PGRs type, concentrations and combinations used are effective for mass propagation of banana variety studied in this experiment.

ROLE OF VENTILATION, CALCIUM AND BORON ON SHOOT TIP NECROSIS AND HYPERHYDRICITY REDUCTION OF IN VITRO ROORSTOOCKS OF PISTACIO ‘BADAMI’ ȘI ‘UCB1’

Shoot tip necrosis (STN) is one of the main physiological disorders in the micropropagation of pistachios. In the current study, the effects of CaNO3.4H2O at 196 mg/L and 291 mg/L, H3BO3 at 196 mg/L and 291 mg/L, and CaCl2.2H2O at 2,980 mg/L on STN and hyperhydricity reduction of Pistacia vera L., ‘Badami’ and ‘UCB1’ rootstocks were assessed, compared to the MS standard medium containing 3% sucrose, 0.7% agar supplemented with benzyladenine (BA) (1.5 mg/L), indole butyric acid (IBA) (0.1 mg/L). For ventilation parameter, filter container vessels with a 50-µm microporous polypropylene membrane (Pardis®) were used. Based on the results, an increase in calcium chloride content of the MS standard medium prevented hyperhydricity in the UCB1 rootstock, whereas it increased STN, yellow leaves, decreasing the multiplication of shoots in the ‘Badami’ rootstock. The results also showed that increasing boric acid from 196 mg/L up to 291 mg/L decreased STN in the UCB1 rootstock and increased this disorder by 37% in the ‘Badami’ rootstock. Ventilation showed no significantly reducing effect on the percentage of STN in the regenerated shoots of the ‘Badami’ rootstock, whilst it decreased the STN of the ‘UCB1’ rootstock to the lowest percentage. For the ‘Badami’ rootstock, CaNO3.4H2O at 196 mg/L led to the highest proliferation rate, shoot height, shoot diameter, and leaf number, but for the ‘UCB1’ rootstock, an increase in the concentration of CaNO3.4H2O up to 291 mg/L under ventilated conditions resulted in an increase in proliferation, shoot height, and shoot diameter.

Multiple shoot induction and regeneration of Vanilla borneensis Rolfe - a critically endangered orchid of Assam, India

In the present investigation, a micropropagation protocol has been developed for Vanilla borneensis Rolfe – a critically endangered orchid through multiple shoot regeneration. Through in vitro multiple shoot regeneration from both nodal and shoot tip explants, maximum (100%) shoot induction was observed. The minimum time required for shoot bud induction was observed from the shoot tip (5–7 days) on medium supplemented with BAP (4.44 mM) + KIN (2.32 mM) as compared to the nodal explants. Maximum multiple shoot regeneration was observed from nodal explants on the medium supplemented with BAP (4.44 mM) + TDZ (6.82 mM). However, maximum shoot length was observed on the medium supplemented with BAP (4.44 mM) + 15% CW and the number of nodes (5.27±0.33) per shoot after 90 days. Maximum (80-100%) of root initiation was observed in almost all the concentrations of NAA. The shortest time of root initiation was found on the medium supplemented with NAA (5.37 mM). Further, acclimatization period was found to be 15 days with 70% acclimatization while 60% of survivability was observed in the field condition. This efficient micropropagation method of V. borneensis could be successfully used for mass propagation as well as conservation of the critically endangered wild orchid.

Grapevine Shoot Tip Cryopreservation and Cryotherapy: Secure Storage of Disease-Free Plants

Grapevine (Vitis spp.) is one of the most economically important temperate fruit crops. Grapevine breeding programs require access to high-quality Vitis cultivars and wild species, which may be maintained within genebanks. Shoot tip cryopreservation is a valuable technique for the safe, long-term conservation of Vitis genetic resources that complements traditional field and in vitro germplasm collections. Vitis is highly susceptible to virus infections. Virus-free plants are required as propagation material for clonally propagated germplasm, and also for the global exchange of grapevine genetic resources. Shoot tip cryotherapy, a method based on cryopreservation, has proven to be effective in eradicating viruses from infected plants, including grapevine. This comprehensive review outlines/documents the advances in Vitis shoot tip cryopreservation and cryotherapy that have resulted in healthy plants with high regrowth levels across diverse Vitis species.

Micropropagation of Hibiscus moscheutos L. ‘Luna White’: effect of growth regulators and explants on nuclear DNA content and ploidy stability of regenerants

Hibiscus moscheutos L., also known as hardy hibiscus, is valued for its medicinal and ornamental attributes. It is usually propagated via seeds or cuttings. The purpose of this investigation was to develop a dependable micropropagation for H. moscheutos ‘Luna White’. To that end, the effect of four explant types (leaf, root, node, shoot tip) and two growth regulators 6-benzylaminopurine (BA) and meta-Topolin (mT) (6-(3-hydroxybenzylamino) purine) on in vitro growth of H. moscheutos was investigated. Genetic stability of the in vitro grown plants was assessed using flow cytometry, and chromosome count was investigated. No shoots were obtained from leaf or root explants. An efficient protocol for micropropagation of H. moscheutos using two explant types, 2-node and shoot tip explants, and two cytokinins (BA and mT) capable of producing true-to-type regenerants was established. Both BA and mT can be used at 2 μM or 4 μM using either 2-node or shoot tip explants. No significant difference was found between the nuclear DNA contents of seed-derived and in vitro grown plants (P < 0.05). The mean 2C DNA and monoploid 1Cx-values of seed-derived plants were 3.25 ± 0.08 pg and 1.62 ± 0.04 pg, respectively, compared with 3.26 ± 0.06 pg and 1.63 ± 0.02 pg, respectively, for in vitro grown plants. The chromosome number of both seed-derived plants and regenerants was determined to be 2n = 2x = 38. The mature regenerants obtained were fertile and phenotypically similar to seed-derived plants.

Clonal propagation of Chrysanthemum morifolium ramat using various explants obtained from field grown plants

A reliable and rapid large scale micropropagation method has been established from the node, shoots tip and leaf explant of Chrysanthemum morifolium growing in field condition. Experiments were conducted to standardize the culture media with plant hormone for multiple shoot proliferation and rooting for obtaining plantlets with uniform characteristics like mother plant in terms of growth and habits. Different concentrations and combinations of auxins (IAA) and cytokinins (BAP, Kin) were used in MS for the above purpose. Maximum shoot regeneration was found in MS treated with 2.0 mg/l BAP both in node and shoot tip explants. In the above combination, nodal explants produced 16 initial shoots. Shoot tip explants produced 12 shoots and leaf segment produced 07 shoots. For in vitro rooting, different concentrations of IBA and NAA were used. Higher rooting percentage was recorded on MS fortified with 1.5 mg/l IBA. The rooted plantlets were hardened and successfully established in the soil. About 90% of the regenerated plantlets survived in the natural environment.

The shoot explant types effect of eleven stevia (Stevia rebaudiana Bertoni)

Explants play an important role in thepropagation system of stevia (Stevia rebaudiana Bertoni). A Completely Randomized Design (CRD) was used in this experiment with factorial pattern consisting of two factors, namely three types of explants (shoot tip, first node, and second node) and eleven accessions of stevia namely a1 (Bogor), a2 (Garut), a3 (Canada), a4 (Tawangmangu), a5 (STG1), a6 (SBG 4), a7 (SBG 10), a8 (SGB 2), a9 (BR5), a10 (SGR 7.5), a11 (TR 3.5). The results showed that shoot tip explant was the best explant than first node and second node for the number of shoots (18.11 shoots), number of leaves (93.49 leaves) and wet weight (3.56 grams). The best accession of shoot height was a10(SGR 7.5) (19.95 cm), the highest number of shoots wasa7(SBG 10) (21.87 shoots), the highest number of leaves wasa7(SBG 10) (138.00 leaves), the heaviest wet weight wasa7(SBG 10) (3.56 grams), the highest leaf chlorophyll content was a10 (SGR 7.5) (0.63 µg mL-1). Accessions with the fastest root initiation time at the rooting stage was a11 (TR 3.5) (4.00 DAC), the highest number of roots wasa10 (TR 3.5) (27.11 roots), the best root length wasa2(Garut) (4.51 cm). Information on the best explant types and stevia accessions in the in-vitro multiplication stage can be used as the basis for stevia breeding programs in Indonesia.AbstractEksplan berperan penting dalam sistem perbanyakan Stevia (Stevia rebaudiana Bertoni). Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan pola faktorial yang terdiri dari dua faktor yaitu tiga jenis eksplan (ujung pucuk, ruas pertama, dan ruas kedua) dan sebelas aksesi stevia yaitu a1 (Bogor), a2 (Garut), a3 (Canada), a4 (Tawangmangu), a5 (STG1), a6 (SBG 4), a7 (SBG 10), a8 (SGB 2), a9 (BR5), a10 (SGR 7.5), a11 (TR 3.5). Hasil penelitian menunjukkan bahwa eksplan ujung pucuk merupakan eksplan terbaik dibandingkan buku pertama dan kedua untuk jumlah tunas (18,11 tunas), jumlah daun (93,49 daun) dan berat basah (3,56 gram). Aksesi terbaik pada tinggi pucuk adalah a10(SGR 7.5) (19,95 cm), jumlah pucuk tertinggi a7 (SBG 10) (21,87 pucuk), jumlah daun terbanyak a7 (SBG 10) (138.00 helai daun), bobot basah terberat a7 (SBG 10) (3,56 gram), kandungan klorofil daun tertinggi adalah GR 7,5 (0,63 µg mL-1). Aksesi dengan waktu inisiasi akar tercepat pada tahap perakaran adalah TR 3,5 (4,00 HST), jumlah akar terbanyak adalah TR 3,5 (27,11 akar), panjang akar terbaik adalah a2(Garut) (4,51 cm). Informasi jenis eksplan dan aksesi stevia terbaik pada tahap multiplikasi in-vitro dapat dijadikan dasar program pemuliaan stevia di Indonesia.