EFFECTS OF JINLU, AN ANTI-JUVENILE HORMONE ON THE GROWTH, ULTRA-STRUCTURE OF THE CORPORA ALLATA AND PROTHORACIC GLAND OF SILKWORM, BOMBYX MORIL

ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｓｅｃｔｐｏｓｔｅｍｂｒｙｏｎｉｃｄｅｖｅｌｏｐｍｅｎｔｃｏｎｓｉｓｔｓｏｆｇｒｏｗｔｈｐｕｎｃｔｕａｔｅｄｂｙａｓｅｒｉｅｓｏｆｍｏｌｔｓｆｏｌｌｏｗｅｄｂｙｍｅｔａｍｏｒｐｈｏｓｉｓ.Ｔｈｅｓｅｍｏｌｔｓａｎｄｍｅｔａｍｏｒ ｐｈｏｓｉｓａｒｅｉｎｉｔｉａｔｅｄａｎｄｃｏｏｒｄｉｎａｔｅｄｂｙｈｏｒｍｏｎｅｓ(Ｒｉｄｄｉｆｏｒｄ ,1 994 ) .Ｉｔｉｓｇｅｎｅｒａｌｌｙａｃｃｅｐｔｅｄｔｈａｔｔｈｅｉｎｔｅｒｐｌａｙｏｆｅｃｄｙｓｔｅｒｉｏｄｓ,ａｇｒｏｕｐｏｆｓｔｅｒｏ…     

Targeting of human aFGF gene into silkworm,<Emphasis Type="Italic">Bombyx mori</Emphasis> L. through homologous recombination

The long-arm and short-arm genes of fibroin light chain (L-chain) of silkworm,Bombyx Mori L., and the gene of human acidic fibroblast growth factor were cloned respectively and subsequently inserted into a transfer vector pVL 1392 used as a tool to target the L-chain region of the silkworm genome. Genomic DNA from their offsprings was extracted and the expected targeting was detected using polymerase chain reaction and DNA sequencing, as well as protein analysis. The results showed that positive events occurred and that the FGF gene was integrated into the L-chain locus through homologous recombination. Project supported by the Scientific Research Foundation for Returned Overseas Chinese Scholars, Education Ministry of China and the Natural Science Foundation of Zhejiang Province (No. 301306), China     

Effect of vertebrate hormones and prostaglandins on growth, silk quality and metabolic activities of Bombyx mori L

The economic importance of silkworm has moved biologists to explore various intricate mechanisms of the action of vertebrate hormones. The dietary administration of several vertebrate hormones and prostaglandins enhanced both developmental and metabolic processes of silkworm, Bombyx mori L. The main objective of sericulture research is to apply the results to achieve superior quality silk and greater output, to apply lab findings to achieve desirable ecenomic results.     

Analysis of bulked segregants to identify molecular markers linked with cocoon weight and cocoon shell weight in the silkworm Bombyx mori L

Two silkworm strains viz, B20 A (high cocoon shell ratio) and C.Nichi (low cocoon shell ratio) were sib mated for 10 generations to determine the homozygosis. Both bulked segregant analysis(BSA) and near isogenic lines (NIL) studies were done to identify the RFLP markers closely linked to cocoon shell parameters. Three hundred and fifty-two random clones were identified as the low copy number sequence and used for identification of Restriction Fragment Length Polymorphic (RFLP) marker linked to cocoon weight and cocoon shell character. In the bulk segregant analysis, DNA from the parents (B20 A, C.Nichi), F1 and F2 progeny of high shell ratio (HSR) and low shell ratio (LSR) were screened for hybridization with the random clones. Polymorphic banding pattern achieved through southern hybridization with different probes indicated the probable correlation of polymorphism with high and low cocoon shell character which are possible landmarks in identifying the putative marker(s) for the cocoon shell character. Out of the 100 probes tried with parents, F1, F2 and their bulks, 10 probes were found to be closely linked to cocoon shell characters.     

Effects of light and temperature conditions on flowering in Mat Rush

The effects of photoperiod and light intensity on flowering in Mat Rush cv. Gangshan 3 were studied. The results showed that treatments with longer day length stimulated flowering significantly and increased stem flowering percentage (SFP). Plants treated with low light intensity at early stage had substantially reduced florets per cyme, SFP, tillers per plant and stem length. At middle and late stage, low light intensity significantly reduced SFP. The principal climatic factors affecting SFP were as follows: mean temperatures (MT) of the third ten-day period (TDP) in December and of the second TDP in February, actual sunlight hours (SH) of the third TDP in February and precipitation of the third TDP in March. A nonlinear simulation model for SFP was established with experimental results and corresponding climatic data (see Eq. (2)). Simulation by the above equation yielded values the same as those observed from 1992 to 2000, indicating its accuracy in describing the relationship between flowering and light and temperature conditions. The interaction between vernalization and SH is also discussed in this paper. Project (No. 981105) supported by the Ningbo City Science Foundation, China     

Impact of light intensity on flowering time and plant quality of<Emphasis Type="Italic">Antirrhinum majus</Emphasis> L. cultivar Chimes White

Shades of different light intensities (29%, 43%, 54%, 60% or 68%) along with control (no shade) were studied to observe their effects on the flowering time and plant quality. A hyperbolic relationship was observed between different light intensities under shade, and time to flowering. The total number of flower buds showed a curvilinear relationship with light intensities. Growth parameters related to the plant characteristics such as plant height, leaf area and plant fresh weight were improved under shading treatments at the expense of flowering time and number of flower buds. However, both linear and polynomial models applied assumed that cultivar Chimes White was equally sensitive to light intensity throughout development.