Studies On Flowering And Growth In Vitro Of Gomphrena Globosa

Tissue cultured seedlings were used as the expe rimental materials to study the effects of nitrogen for m and concentration on the gr owth and in vitro flowering induction of aseptic seedling of Gomphrena globosa.On this basis,research the effects of sucrose concentration,NAA,6-BA and TIBA and NP A on flowering induction and growth of aseptic seedling.The results showed:(1)Compared with the ammonium nitrogen(NH4+),the nitrate nitrogen(NO3-)as the sole nitrogen source was more favorable for the growth and in vitro flowering induction,whereas best was observed with the presence of both NH4+ and NO3-;(2)In the presence of 20 mmol/L NH4+(NO3-)and 5 mg/L PP333,the growth was generally increased with the content of NO3-(NH4+),and reached the maximum height of 5.91 cm in the culture medium with 40 mmol/L NO3-+ 20 mmol/L NH4+(nitrogen content of MS medium),whereas th e leaf num ber and flow ering rate were first in creased and then decreased with the total nitr ogen content,and reached their respective maxim ums of 10.7 per seedling and 38.89 % in the cu lture medium with 20 mmol/L NO3-+ 5 mmol/L NH4+;(3)The results of nitrogen content and form ratio showed that the maximum flowering rate of 39.95% was induced in the medium of 5 mmol/L total nitrogen with the ratio of ammonium to nitrate as 4/1;in contrast,th e maximum height and leaf num ber of 8.52 cm and 13.38 respectively.achieved in the medium with total nitrogen of 35 mm ol/L and the ratio of ammonium to nitrate as 4/1.The flowering rate of as eptic seedling was in significant positive correlation with the ratio of nitrate nitrogen to ammonium nitrogen,but negative correlation with the to tal nitrogen c ontent and plant height.In addition,the nitrogen content and th e ratio of nitrate nitrogen to ammonium nitrogen in the c ulture medium also significantly influenced the root growth of aseptic seedlings.(4)The flowering rate was increased with the incr ease of sucrose concentration,the m aximum flowering rate reached 80.72% at the sucrose conten t of 80g/L;at the sucrose content of 0g/L,the aseptic seedling grew very bad and lea ves are all yellow from base to tip while they grew very well in the range of 20 to 80g/ L;the plantlet height and leaf number mainly increased and then decreas ed with the in crease of sucrose concen tration where,and respectively reached the maximum 3.83 cm and 7.67 peer seeding at the sucrose content of 20g/L.(5)6-BA significantly influenced the fl owering rate and the plantlet height,and highly significantly influenced the leaf number,the maximum flowering rate reached 60.14%,the average leaf number was larger,the flower were bigger and plantlet grew better at the 6-BA content of 1.0 mg/L;NAA did not have significantly influence on the flowering rate,the plantlet height and the l eaf number.(6)Auxin polar transport inhibitors significantly influenced the flowerin g rate and inhibit flowering.The effects of inhibiting flowering increased with the increase of c oncentration of TIBA and NPA;and add TIBA and NPA at the content of 10 um ol/Lin the medium,the flowering rate respectively decline 77.00% and 62.50% compared with the control group.At the same content of TIBA and NPA,TIBA inhibit flowering wa s more significantly..The auxi n polar transport inhibitors significantly influenced the leaf number and did not signific antly influenced the plantlet height.In addition,the auxin polar transport inhibitors also significantly influenced the root growth of aseptic seedling.