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Physiological changes in the diapuse eggs, treated with HCI after chilling Chilling (cold storing) diapause eggs at 5"C for less than 30 days is known to be insufficient to terminate diapause. However, when HCltreatment is performed on these chilled eggs, diapause termination is completely achieved. This treatment brings about the following important physio-biochemical changes. 1. To begin with, the oxygen consumption increases and triggers the embryo lor an active embryo genesis. 2. ln HCltreated diapause eggs (alter 30 days of chilling) the two polyols sodcitol and glycerol reconvert to glycogen. The level of glycogen increases upto 6 or 7 days of incubation with a subsequent decrease upto hatching. On the contrary, in the eggs treated with HCI after 20 hrs. of oviposition, glycogen level decreases continuously upto hatching. 3. The sorbitolcontent remains unchanged on the first day and then decreases dramatically during lhe next 2 days after HCI lreatment, leaving only trace amounts. 4. The NAD-SDH (NAD dependent sorlcitoldehydrogenase) activity increases rapidly reaching a maximum value seven days afterthe lreatment and then decreases untilone day before hatching. Thus there is a close correspondence between the time of the increase in NAD-SDH activity and the degradation of sorbitol during the termination of diapause. 5. The activities of mitochondrialGlutamate-oxaloacetate transaminase (GOT) and malate dehydrogenase (MDH) increase in diapause eggs which are chilled at 5oC lor more than 20 days. Further, the HCI lreatment brings about an abrupt increase in the activites of mitochondrial GOT and MDH with the maximum effect appearing, two days after the treatment. The cumulative effect of these biochemical reactions ameliorales the hatching efficiency of the chilled and acid treated diapause eggs. Conclusion lnconclusion, aquestionmayarisewhetherthehotacidtreatmentisbetterorthecoldacidtreatment. Strange enough, no authentic literature is available to support the superiority of any of these methods. However, our clear answer is both. Both the methods when carried out properly have been found lo be equally elficient and are bound to give excellent resulls. The ultimate choice is thus left to the user who should take a final decision considering the following points. a. Type of eggs to be treated (purely uni/ bivoltine or mixed) b. Age of the eggs for treatment c. Season ol treatment (during summer rnonths there may be a tendency in fhe eggs to show some degree of polyvoltinism and vice versa in the winter) d. Quantity of eggs to be treated and time at lhe disposal and e. Availability of infrastructural facilities. 39
REFERENCES AYUZAWA, C. SEKIDO, t., YAMAKAWA, K., SAKURAI, U., KURATA, W., YAGINUMA, Y AND TOKORO, Y. (1972). Hand Book of <strong>Silkworm</strong> Rearing, Fuji Publishing Co., TOKYO, JAPAN. cHtNo, H. (1958) . Carbohydrate metabolism in the diapause eggs o{ the silkworm , Bombyx mori. lll - Conversion ol glycogen into sorbitol J. INSECT PHYSIOL. 2, 1 -12. cHrNo, H. (1960). Enzymatic pathways in the formation of sorbitol & glycerol in the diapausing egg of the silk worm, Bombyx mori. l- On the polyol dehydrogenases, J. INSECT PHYSIOL.5, .1-15 FUJIWARA, T. & KAGAWA, T (1984). Control ol Nosema bombycis parasitising silkworm eggs by lreatments with hydrochloric acid or exposure to various lemperatures. J. SERCULT. SCI. JAPAN. 53, 394.397. FURUSAWA, T., SHIMLZU,K. & YANO, T. (1987). Controlof polyol metabolism and diapause controlof Bombyx eggs by anaerobiosis. J. SERICULT. SCI. JAPAN. 56, 202-209. JOLLY, M.S. (1983). Organisation of lndustrial Bivoltine Grainage for Tropics. SERICULT. PROJECT-?. Central Sericultural Research & Training lnstitute, Mysore. E(AGEYAMA, T. & OHNISHI, E. (1971). Carbohydrate metabolism in the eggs of the silkworm , Bombyx mori,lAbsence of phosphof ructokinase in the diapause eggs. DEVL. GROWTH'DIFFERENT. 1 3, 97-1 06. KAt, H & HASEGAWA, K. {1972). Studies on the mode of aclion of the diapause hormone with special relerence to lhe protein metabolism in lhe silkwo rm, Bombyx mori.L.lll - Ellects of acid treatment and detergents on "ESTEFIASE' A" in diapause eggs. J. SERICULT. SCI. JAPAN, 41,253.262. KAl, H and NlSHl, K. (1976). Diapause developmenlin Bombyx eggs in relation to "Esterase A" activity. J. TNSECT PHYS|OL.22, 1315-1324 KAl,land HAGA, Y. (1978) Further studies on "esterage A" in Bombyx eggs in relation to diapause development. J. SERICULT SCI. JAPAN. 47, 125-133 KlM,S. (1987). Changes in egg-shell permeability to oxygen during the early developmental stages in diapause eggs ol Bombyx mori. J. IN SECT PHYSIOL. 33, 229-235. KtM, S., SHIKATA, M & KAl, H (1981). Egg-shell lipids in relation to water evaporation and diapause in the silkworm Bornbyx mori. J. SERICULT. SCI, JAPAN,50, 84-1 00. 4:O
Page 2 and 3: A Treatise on the Acid Treatment of
Page 4 and 5: Preface Acid treatment of silkworm
Page 6 and 7: lntroduction The diapause, in insec
Page 8 and 9: Selection of the acid For consisten
Page 10 and 11: Generation of heat during acid prep
Page 12 and 13: Preparation of formalin solution :
Page 14 and 15: Determination ot the age ot eggs :
Page 16 and 17: 1. The lemale rnoth laying eggs. 3.
Page 18 and 19: W - ,'' ri;. tI ;i*r ill ii r i*t i
Page 20 and 21: \ j i x :li'i:L :i 16 16. The cold
Page 22 and 23: ':;:':i,!:i.;: .i.;:.;..rril.l:r1 o
Page 24 and 25: Disadvantages : 1 Needs suflicientl
Page 26 and 27: 3. Acid treatment should not be per
Page 28 and 29: Dipping duration The dipping durati
Page 30 and 31: to measure specif ic gravity by uti
Page 32 and 33: lnitiation & Establishment of Diapa
Page 34 and 35: esterase-A. This suggestion is like
Page 38 and 39: KURATA, S, KOGA, K and SAKAGUCHI, B

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