Dalbergia and Albizia: Plantlet production via tissue culture, karyological evaluation, and seed anatomy with scanning electron microscopy

A publication by the American National Academy of Sciences (1979) outlined some of the urgent research need for a great variety of economically important woody species whose remaining genetic resources need urgently to be collected and conserved. I established a viable regeneration system via tissue and cell suspension culture for Albizia lebbeck and Albizia falcataria, two important wood yielding leguminous tree species. I standardized the culture medium by adding different growth factors and growth stimulators to obtain callus from the leaflet explants of the tree species. I found that the optimum use of casein hydrolysate (w/v) and coconut milk (v/v) in addition to 6-BAP and IBA could induce morphogenesis and somatic embryogenesis in the cultured tissue. This reports the first observation of somatic embryogenesis of A. lebbeck using leaflets as the explants. On MS media modified with 6-BAP (6 mg/l), NAA (0.02 mg/l), PVP (0.5%) and coconut milk (5% v/v) the explants produced proembryoids, other hormonal combinations produced various callus forms. I recorded the different stages of embryogenesis and plant development under the dissecting scope and SEM. After hardening and transferring, the trees grew more than 25 feet tall within few months outside the greenhouse.;The application of seed data is increasingly included and discussed in revisions and circumscription of angiosperm families and orders. I cut sections of the seeds of 24 species of 4 leguminous genera to study the seed anatomy under the dissecting microscope and the SEM. It was possible to observe the cellular organization of the epidermis, endosperm and internal structural details of the seeds on study with SEM. Main distinguishing characters observed were uniseriate or multiseriate epidermis, epidermal projections, and number of rows and nature of columns of hypodermal layer, especially the nature of endosperm. This study provided enough characteristic features to isolate the species that will help in further application of seed data in different fields.;I analyzed the karyotype of the three leguminous trees Albizia lebbeck, A. falcalaria and D. sissoo. I studied the somaclonal variation in the cultured tissue of D. sissoo. The aged tissue in culture develops certain cytological instabilities that are dependent upon the frequency of subculture as well as the age of the tissue. Using optimum concentrations of coconut milk and casein hydrolysate I could reduce Chromosomal abnormalities that could also reinstate the regeneration potential in the aged cultured tissue.