Micropropagation of Capparis decidua through In Vitro Shoot Proliferation on Nodal Explants of Mature Tree and Seedling Explants
In vitro clonal propagation of Capparis decidua was achieved using nodal explants from mature trees, and cotyledonary node, cotyledon and hypocotyl explants taken from the seedlings. Explants cultured on MS medium supplemented with BAP showed differentiation of multiple shoots and shoot buds in 4–5 weeks in the primary cultures. The medium with BAP (5 mg/l) was the best for shoot bud proliferation from the nodal as well as seedling explant. Shoot multiplication was best on cotyledonary node. In the nodal explants shoot multiplication was best on medium supplemented with 5 mg/l BAP and after second subculturing further multiplication of shoot buds was highest on the medium containing 3 mg/l BAP. Shoots were separated from mother cultures in each subculturing for rooting. Rooting was best achieved using 1 mg/l IBA in the medium. Rooted plantlets were transferred td earthen pots with garden soil and peat moss mixture.
Clonal propagation of mature elite trees of Commiphora wightii
Elite trees of Commiphora wightii (Arnott) Bhandari were selected from the wild on the basis of their content of guggul, an oleoresin. The selected tree was micropropagated through forced axillary branching on Murashige and Skoog's (MS) medium supplemented with benzyladenine (BA) and kinetin. Highest frequency of shoot formation was achieved on MS medium supplemented with 17.8 μM BA, 18.6 μM kinetin, 100 mg l-1 glutamine, 10 mg l-1 thiamine HCL and 0.3% activated charcoal. Seasonal changes affected the shoot proliferating potential of the initial explants in vitro. Transfer of shoots to a medium containing a lower concentration of BA (1.8 μM) and kinetin (1.9 μM) before rooting markedly stimulated shoot elongation. Shoots could be rooted by treating them with both indoleacetic acid and indolebutryic acid for 24 h in darkness and transferring them to a low-salt basal medium with activated charcoal. After rooting, transfer to a half-strength White's (modified) medium was necessary for further development of the plantlet. Regenerated plantlets were successfully established in soil.
The relation between the clay content and certain physical properties of a soil
A simple experimental method has been described for measuring certain physical constants of soil, using small brass boxes into which soil passing a sieve of 100 meshes to the inch has been packed by hand. The quantities determined are: (1) The weight of unit volume (100 c.c.s.) of air-dry soil, or the apparent specific gravity. (2) Amount of water taken up by unit weight of soil. (3) Pore space. (4) Specific gravity of the soil. (5) The volume expansion of unit volume (100 c.c.) of soil when saturated. The results for one soil only are given, and discussed, to illustrate the method. With the co-operation of the Science Masters Association it is being applied to a number of soils by various schools. The particular soil used was obtained in six depths as follows: 0–6–12″, 12–18″, 18–24″, 2–3′, 3–4′, and the above constants were determined on each depth. It was shown that (1) and (4) varied inversely with the percentage of clay in the soil, while (2), (3), and (5) varied directly with the clay percentage. The effect on the constants of the larger quantities of organic, matter present in the top two layers of soil was, weight for weight, approximately equal to that of the clay, except in the volume expansion results where the effect if any was within experimental error. It is possible that the fraction fine silt II, whose upper limit of diameter is ·005 mm., has similar effects to the clay fraction.