In Vitro Propagation of Selected Sugarcane ( Saccharum Officinarum L . ) Varieties ( C 86-165 and C 86-12 ) Through Shoot Apical Meristem
Sugarcane (Saccharum officinarum L.) is monocotyledonous crop plant that belongs to the Poaceae family that mostly propagates through conventional methods. However, conventional propagation lacks rapid multiplication procedures to commercialize newly released varieties within a short period of time. Hence, the objective of this work was to optimize in vitro micro propagation protocol for two sugarcane varieties (C 86-165 and C 86-12) using shoot apical meristem explants. The two varieties were cultured on MS medium supplemented with different concentrations of growth regulators on shoot initiation, multiplication and root induction stages. Analysis of variance (ANOVA) revealed that the two varieties showed statistically significant difference in their response to the various hormonal treatments with regard to the parameters measured. For initiation stage vars. C 86-165 and C 86-12 performed best on 1.0 mg/l and 0.5 mg/l of BAP, respectively. On the other hand, multiplication stage was best in MS media enriched with 2.0 mg/l BAP + 0.5 mg/l NAA and 1.5 mg/l BAP + 0.5 NAA as manifested in terms of number of shoots and shoot length per explants after four weeks of culture for vars. C 86-165 and C 86-12, respectively. With regard to root induction, best rooting response in terms of mean root number, mean root length, mean fresh weight and mean dry weight was achieved in 1/2 MS media enriched with 2.0.mg/l NAA and 1.0 mg/l NAA after four weeks of culture for vars. C 86-165 and C 86-12, respectively.
Comparative Studies on Field Performance of Micropropagated and Conventionally Propagated Sugarcane Plants
The tissue culture derived sugarcane var. CoJ 64 plants attained better height, millable cane height and a greater number of live buds to conventionally raised plants. Further, the plants raised in vitro showed 13.2% increase in cane yield and 11.03% sugar recovery as compared to conventionally propagated sugarcane under parallel agronomic practices in the field, advocating suitability of seed cane programmed through tissue culture. Key words: Comparative studies, Field performance, Sugarcane, Micropropagation DOI = 10.3329/ptcb.v16i1.1102 Plant Tissue Cult. & Biotech. 16(1): 25-29, 2006 (June)
Gut immunity in Lepidopteran insects.
Lepidopteran insects constitute one of the largest fractions of animals on earth, but are considered pests in their relationship with man. Key to the success of this order of insects is its ability to digest food and absorb nutrition, which takes place in the midgut. Because environmental microorganisms can easily enter Lepidopteran guts during feeding, the innate immune response guards against pathogenic bacteria, virus and microsporidia that can be devoured with food. Gut immune responses are complicated by both resident gut microbiota and the surrounding peritrophic membrane and are distinct from immune responses in the body cavity, which depend on the function of the fat body and hemocytes. Due to their relevance to agricultural production, studies of Lepidopteran insect midgut and immunity are receiving more attention, and here we summarize gut structures and functions, and discuss how these confer immunity against different microorganisms. It is expected that increased knowledge of Lepidopteran gut immunity may be utilized for pest biological control in the future.