Forest Research Institute

About: Forest Research Institute is a facility organization based out in Dehra Dūn, India. It is known for research contribution in the topics: Population & Forest management. The organization has 5320 authors who have published 7625 publications receiving 185876 citations.

Micropropagation of Dendrocalamus asper by shoot proliferation using seeds

Abstract: An efficient and reproducible procedure for the large-scale propagation of Dendrocalamus asper is described. High-frequency direct shoot proliferation was induced in aseptic seed cultures of D. asper on modified Murashige and Skoog's (1962) medium supplemented with 1.0–10.0 mg/l benzyladenine (BA). Multiple shoots (1–25) were formed within 5 weeks of seed culture without root formation. The shoot-forming capacity of seeds was influenced by the BA concentration in the medium. Proliferating shoot cultures were established by repeatedly subculturing shoots in propagules of 3 shoots each. A multiplication rate of 15–16 fold was achieved on MS medium +3.0 mg/l BA. Roots were formed on excised propagules of 3–5 shoots when transferred to MS medium containing 10.0 mg/l indole-3-butyric acid (IBA) or 3.0 mg/l 1-naphthaleneacetic acid (NAA). Plantlets were hardened, acclimatized and established in soil, where they exhibited normal growth.

Mechanical constraints on lignin deposition during lignification.

Abstract: Summary. The ultrastructure of lignifying cell walls in Pinus radiata D.Don was investigated using potassium permanganate staining and transmission electron microscopy. Lignin deposition occurred at numerous discrete sites within various cell wall regions, suggesting the presence of some initiating agent at these sites. In the middle lamella region, lignin deposition occurred by addition of protolignin monomers to spherical particles of lignin. Lignification was completed by expansion of these spherical particles, initially forming irregular patterns of lignification followed by infilling of adjacent areas. In contrast, lignification in the secondary wall occurred by deposition of protolignin monomers onto the ends of expanding lignin lamellae between cellulose microfibrils leading to greatly elongated patches of lignin due to the greater rate of deposition along the micro fibril axis compared to that across it. It is concluded that the cellulose matrix in which lignin deposition occurs, in the secondary wall, can exert a mechanical influence which limits the rate of lignin deposition in the direction perpendicular to the microfibril axis.

Interactive effects of leaf age and self-shading on leaf structure, photosynthetic capacity and chlorophyll fluorescence in the rain forest tree, Dryobalanops aromatica.

Abstract: In the tropical canopy tree, Dryobalanops aromatica Gaertn. f., upper-canopy leaves (UL) develop under sunlit conditions but are subjected to self-shading within the crown as they age. In contrast, lower-canopy leaves (LL) are exposed to uniform dim light conditions throughout their life span. By comparing leaf morphology and physiology of UL and LL, variations in leaf characteristics were related to leaf age and self-shading. Mass-based chlorophyll (chl) concentration and the chlorophyll/nitrogen (chl/N) ratio were lower and the chl a/b ratio was higher in UL than in LL. In UL, the chl/N ratio gradually increased and the chl a/b ratio gradually decreased with leaf aging, whereas these ratios remained unchanged with leaf age in LL. The effective quantum yield of photosystem II (PSII) (DeltaF/F(m)') at a given irradiance remained unchanged with leaf age in LL, whereas DeltaF/F(m)' changed with leaf age in UL. These data indicate N reallocation within the leaves from carbon fixation components to light harvesting components and a dynamic regulation of photochemical processes of PSII in response to increased self-shading of UL. Despite the difference in light environment with leaf age between UL and LL, maximum photosynthetic rates and nitrogen-use efficiency decreased with leaf aging in both UL and LL. Constancy in the chl/N ratio with leaf age in LL indicated that the decrease in photosynthetic capacity was caused by effects other than shading, such as leaf aging. We conclude that N reallocation and acclimation of PSII to self-shading occurred even in mature leaves, whereas the change in photosynthetic capacity with leaf age was more conservative.