20 August 1991, Volume 5 Issue 04
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J4. 1991, 5(04): 193-198. https://doi.org/10.11869/hnxb.1991.04.0193
The tobacco anthers at uninucleate eccentric stage were irradiated by 60CoY-rays for the purpose of inducing desirable mutants.The results showed that the induction frequency of plantlets increased following 1kR of 60Co γ-rays treatment.Howevr,the time of plantlet induction was delayed and the percentage of responding anthers as well as the number of plantlets induced per anther significantly decreased after 3kR of 60Co γ-ray radiation which was considered as a semilethal exposure.The plantlet numbers induced per anther were extremely low following 6kR of 60Coγ-ray radiation.A white flower mutant appeared in the induced progenies.-The tobacco leaf quality of,this mutant were significa'ntly imporoved as compared with its parental line.The mutant line has been tested and proved to have commercial value though the resistance to the black shank of tobacco slightly decreased as compared with the parental line.
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J4. 1991, 5(04): 199-204. https://doi.org/10.11869/hnxb.1991.04.0199
Dry seeds of a.indie a rice variety were irradiated by argon ion beam (E=400MeV/u,LET=117keV/μm)with various doses.The injurious effects in M1 generation were observed,and the dose-seedling survival curve as well as dose-fertility curve were established,which showed that D50-s and D50-f were 93.7 Gy and 67.0 Gy respectively.The mutants with variation in quantitative or morphological characters were sought in M2 generation and the results indicated that treatments at dose from 60 Gy to 120 Gy were effective in inducing mutation,especially for mutation of semidwarf,ear-lyness,and large grain,but the highest mutation frequency was observed at 90 Gy treatment.Also,more than one mutated-characters were frequently found in one single plant.An analysis of nine isozymes were conducted to d'etect linkage between isozyme loci and loci controlling mutated characters,and the alteration of electrophoretic banding patterns was observed in most mutants surveyed,when compared with original variety,at one or two enzymes of PGD-1 and PGI-2,which related to mutation on characters of grain shape and plant height respectively.
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J4. 1991, 5(04): 205-209. https://doi.org/10.11869/hnxb.1991.04.0205
The relationship between cellulose content of the normal mature fiber of cotton and its fiber strength had been analysied.By using 3H labelling te-chnique,the effect of cellulose deposition speed on the fiber strength had been studied.The sellulose content of normal mature fiber of all species ( varieties ) was higher than 85%,but it had no significant effect on the fiber strength.When the cellulose content was lower than 80%,the fiber strength increased with increasing cellulose content.The deposition speed of cellulose had significant effect on the fiber strength.
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J4. 1991, 5(04): 210-214. https://doi.org/10.11869/hnxb.1991.04.0210
Field experiment and 15N-labelled urea microplot experiment on loam soil show that the yield increased by superhigh quota irrigation treatment is not significant as compared with normal quota irrigation treatment with no topdressing.However,after topdressing urea,the wheat yield of super-high quota irrigation treatment is even less than that of normal quota irrigation treatment.The superhigh quota irrigation decreases the efficiency of topdressing urea obviously.Under the irrigating quota of 70m3/mu,the efficiency of topdressing urea is the highest and the loss rate is the lowest.The efficiencies of topdressing urea at the irrigating quota of 40m3/ mu and.100m3/mu have decreased by 4.74% and 0.64% respectively;while the loss rates have increased by 4.63% and 5.54%.
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J4. 1991, 5(04): 215-218. https://doi.org/10.11869/hnxb.1991.04.0215
Observations of translocation of 14C-assim.ilates at different time by barley leaves in different leaf positions were conducted in field conditions by means of 14C tracer technique.The results indicated that the amount of 14C-assimilates exported from leaves increased with the change of leaf position from low to top and the same pattern was observed at different time.The exporting amount of 14C-products assimilated at 8:00 was much more than that assimilated at 12:00 and 18:00 with the change of leaf position from low to top,only a little difference of exporting amount of 14C-assimilates was observed among the different labelling time.
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J4. 1991, 5(04): 219-223. https://doi.org/10.11869/hnxb.1991.04.0219
The optimum temperature of photosynthesis tended to become higher following the growth of cucumber.The optimum temperature was 30℃ at the early growth stage and 35℃ at the late growth stage.Stomatal resistance decreased and transpiration rate increased with increasing of the temperature.Most of the 14C-photosynthetic products in leaves were transported out at 30℃ during the day.After one night,more photosynthetic products were transported out under higher temperature.From the early to the middle growth stage,most of the 14C-photosynthetic products were transported to fruits at 30℃.But caulis,leaves and apical point obtained most of the photosynthetic products at 35℃.At the late growth stage most of the 14C-photosynthetic products were transported to fruits at 35℃.At 25℃,caulis and leaves got more 14C-photosynthetic products.
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J4. 1991, 5(04): 224-228. https://doi.org/10.11869/hnxb.1991.04.0224
Hair progesterone contents during gestasion and milk progesterone levels during oestrus cycle in Saanen (S),crosses F1(S×Chengdu Mah) and F2 (S×(S×Chengdu Mah) ) goats were determined using the RIA kit.The results showed that progesterone in goats hair could be detected using the RIA kit.In pregnant goats,hair progesterone contents was correlated with the milk progesterone profile during 1-28 days after oestrus (r= 0.5458,P<0.01 ).In non-pregnant goats,similar correlation was observed (r=0.7832,p<0.01).After milk samples were collected 22 days,3.9ng /ml of progeste'rone was taken as the discriminatory level,and precision of pregnancy and non-pregnancy diagnosis were 82.4% and 100% respectively.After hair samples were collected 22 days,3.7ng/50mg of progesterone was taken as discriminatory level,and precision.of pregnancy and non-pregnancy diagnosis were 77.8% and 100% respectively.During gestation,hair progesterone content increased gradually from day 30 (5.67±0.98ng/ 50mg hair) to day 120 (9.85±1.20ng/50mg ) and decreased rapidly from-8 (before parturition,7.73±1.91ng/50mg ) to day 0 ( parturition,4.93±0.25 ng/50mg)
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J4. 1991, 5(04): 229-232. https://doi.org/10.11869/hnxb.1991.04.0229
The ginsengs irradiated by 1 or 2 kGy of r-rays have been stored for 6 months under room tempereture.Its freshening rates was 86.67% and 88.33 %,repectively.The saponin content was maintained.The irradiated ginsengs had the vigour of sap fully and beautiful colour.Therefore they can be stored much longer for sell.The toxicity test showed that there was no toxicity for irradiated ginsengs.
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J4. 1991, 5(04): 233-238. https://doi.org/10.11869/hnxb.1991.04.0233
The plasmids contents from 9 varieties including 14 strains of Bacillus thuringiensis have been detected by modified Birnboim's method.Southern blot hybridization analysis has been performed in the 14 strains,using variety subtoxicus plasmid DNA as probe.B.thuringiensis var.tianmensis isola-ted from Tiamen county,China,contains 14 plasmid bands in agarose gel electrophoresis,and the delta-endotoxin was located mainly in 60 MD plasmid.The Bgl Ⅱ restriction fragments of the plasmid were ligated into.the Bam H I site of the vector pBR322,and transformed into E..coli HB.101.Of.1800 transformants,219 Apt Tcs clones have been examined.Reco-mbinants for production of antigen reacted with antibody which was made against B.thuringiensis var.kurstaki HD-1.crystals we're screened by ra-dioimmunoassay.Among them seven strains were shown to produce crystal delta-endotoxin protein antigen and hybridize with pES 1 plasmid;pTCC 65 and pTCC 18 are toxic to larvar of corn borer (Ostrinia furnacatis),suggesting that these recombinants carried the crystal protein gene with have been expressed.
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J4. 1991, 5(04): 239-245. https://doi.org/10.11869/hnxb.1991.04.0239
In this paper we found that the nitrogenase activity and the rate of H4+-derepression in Anabaena 7120 were declined with the increase of concentration of sodium chloride in culture solution.Over 1.5×10-1mol/L of sodium chloride there was a marked inaction in the nitrogenase activity and rate of NH4+-derepression.Under weak light condition or in presence of ph-otosynthetic inhibitors,such as DNP and salicyladoxime,MSX and chlor-amphenical,a great inhibition of nitrogenase activity arid rate of NH4+-der-epression of Anabaena influenced by increase of sodium chloride in culture solution were observed.But enhancing effect,occurred when external sucrose was added to culture solution.The characteristics of nitrogen fixation in Anabaena influenced by sodium chloride,depend upon the physiological conditions.It has been observed that.1.The addition of H2 together with O2 could accelerated nitrogenase activitty and NH4+-derepression of,Anabaena,influenced by higher concentration of sodium chloride,while depress by the oxygen alone.2.Under an atmosphere containing 5% CO2 or 5% CO2 and 20% N2 the nitrogenase activity and rate of NH4+-derepression in Anabaena influenced by sodium chloride in medium were decreased,but were promoted in normal cells of Anabaena.
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J4. 1991, 5(04): 246-250. https://doi.org/10.11869/hnxb.1991.04.0246
We have probed four positive clones containing histone H3 gene of maize (Zea mays) from its EMBL 3 genomic library in situ,hybridization and dot blotting.The histone H4 gene was also obtained through poly-merase chain reaction (PCR) and cloned in pUC19 plasmid.All of these genes could be used in plant or animal breeding for improvement of the transformation efficiency.
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J4. 1991, 5(04): 251-253. https://doi.org/10.11869/hnxb.1991.04.0251
