Handbook of Plant and Crop Physiology

also contribute. Because root development and callus formation occur simultaneously, it is believed that

the formation of callus is essential for root development. In reality, these two are entirely different phe-

nomena. Sometimes roots develop even without callus from the nodes. Callus formation is sometimes

beneficial in varieties that are slow to root because it provides a protective layer, preventing the cutting

from becoming desiccated and decayed. Sometimes the callus interferes with the absorption of water by

the cutting. In our investigations, rooting did not start, instead, callus formation was observed after 1 week

of treatment. The callus was creamy white and had a granular texture.

The rate of sprouting of vegetative buds is of primary consideration in introducing a variety or

species in an area. Mulberry varieties grown in Mysore and West Bengal sprout throughout the year, fa-

cilitating the attempts of sericulturists to rear the silkworms year-round. The axillary buds vary in size,

shape, and position from variety to variety.

Thus the rooted stem cuttings are more useful than seed sowing because the survival of a rooted cut-

ting is far better than that of the delicate seedlings in the stressful environment of the desert.

IV. SUMMARY

In India, propagation through stem cuttings is the most common method. It is restricted to varieties that

are fully acclimatized to local environmental conditions. Plants that have qualities such as a nutritious leaf

for silkworms, higher yield, quick growth for establishment, and resistance to diseases and insect pests

and drought-resistant varieties such as Atriplexare selected.

Plant hormones are identified as growth promoters (auxins, gibberellins, and cytokinins). They usu-

ally exist in plants at a concentration lower then 1 M, above which they are generally considered

supraoptimal. Mulberry varieties that do not ordinarily produce roots from a cutting are induced to root

with application of root hormones. The chemicals used for this purpose are IAA, NAA, and IBA.

The objective of using growth regulators in mulberry and Atriplexwas to increase rooting in cuttings,

hastening root initiation and increasing the number of roots per cutting. IAA and NAA were found better

for producing roots. Atriplexproduces the maximum number of roots with NAA, followed by IBA and

least in IAA. The results of field experiments showed that NAA is more effective than IBA and IAA. The

appearance of more new leaves with an increased percentage of rooting also points to better possibilities,

with the emergence of more new leaves on the cuttings. The greater number of roots and leaves per cut-

ting may also help the cuttings to survive when sown under natural field conditions.

These cuttings collected from wild and cultivated varieties dried out in all treatments with growth

regulators in the summer season in both growth room and garden pot experiments. In the rainy season the

experiments in the growth room failed as the cuttings dried without any sprouting, but in the garden pots

VEGETATIVE PROPAGATION OF SALTBUSH AND MULBERRY 139

TABLE 4 Effect of Different Concentrations of IAA and NAA on Bud Sprouting (BS), Initiation of Leaves
(L), and Number of Inflorescences (I) on Stem Cuttings of Morusspp. (Wild Var.) from Chopasni in Growth
Room (1993)

Total
Concentration buds on Dec. 12 Dec. 21 Dec. 30 Jan. 10
(ppm) cuttings BS L I BS L I BS L I BS L I

IAA
10 7 2 3 1 1 5 4 4 7 7 8
21 11 1 112
20 8 1 1 2 5 4 4 7 6 4 10 8
11 112121 13
NAA
10 8 3 3 1 5 8 9 6 9 6 8 10 8
1 1 11 12 2 1 12
20 7 2 3 1 1 4 3 2 4 4 3
1 1 11 11 1 22
Control 5 1 2 2 2 3 3 3 3 4 4
11 111111111