Investigation on the Sterility Changeover of Male Sterility Line CMS7311 in Heading Chinese Cabbage

Sterility changeover induced by low temperature in male sterility line CMS7311 of heading Chinese cabbage ( Brassica campestris L. ssp. penkinsis) was investigated under constant temperature, day/night alternating temperature in light-growth-incubator and outdoor natural day/night alternating temperature respectively. It showed that the sterility of CMS7311 has significant change with temperature. The constant temperature of 6 - 12 degreesC was suitable to induce the changeover of sterility (CGS) of CMS7311 ; the shortest treatment time for CGS induction at this temperature was 3 d. The significant value of sterility changeover of CMS7311 occurred at the constant temperature of 6 - 9 degreesC after treatment for 6 - 9 d. The intensity of CGS was stronger under constant temperature than under alternate temperature, but the shortest treatment time inducing CGS has no difference between them. When treated for 9 d under the day/night alternating temperature of 11/7 degreesC, its sterility could also turn to normal fertility (near to sterile grade I or zero). In normal condition, the interval from the end of temperature treatment to the beginning of CGS induction was 10 - 16 d. In the condition of natural day/night alternating temperature, the lower limit of temperature for effective CGS induction was at the daily mean temperature ( DMT) of 3. 5 - 6. 8 degreesC, and the shortest treatment time which could induce the sterility changeover was also longer than that under constant temperature, being 11d at DMT of 1.5 - 3.1 degreesC. In addition, for the apical dominance, the flower bud on the first lateral branch showed the CGS 8 - 10 d later than the flower bud on the main stem under the same temperature with the same days of treatment. The intensity of CGS of CMS7311 on the first lateral branch was also weaker than the flower bud on the main stem.

Phytochemicals and antioxidant activity in four varieties of head cabbages commonly consumed in China

Head cabbage(Brassica oleracea var.capitata)is a cruciferous leafy vegetable consumed commonly in China.It has been suggested that diets rich in cabbages play an important role in disease prevention.The phytochemicals as well as antioxidant activity of four typical varieties of head cabbages in China were systematically investigated.Sinapic acid was the most abundant phenolic acid in all samples followed by iso-ferulic acid.Most phenolic acids in red head cabbage were significantly higher than in other head cabbages.The 5-CH3-H4 folate contents in all samples were much higher than folate.Conical head cabbage contained the highest amount of folic acids while red head cabbage had the lowest.Cyanidin was the only anthocyanidins found in red head cabbage with the content of 44.52 mg 100 g^(−1)fresh weight(fw).Total isothiocyanates in flat head cabbage was significantly higher than other head cabbages.Red head cabbage had the significant the highest level of total phenolics and flavonoids with the values of 153.94 mg gallic acid equivalents·100 g^(−1)and 51.32 mg rutin equivalents·100 g^(−1),respectively,while flat head cabbage had the lowest level.Red head cabbage exhibited the highest antioxidant activity as measured by 1,1-diphenyl-2-picryl-hydrazyl(DPPH)and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt(ABTS)radical scavenging and ferric ion reducing antioxidant power(FRAP)assays with the values of 69.82,87.23%and 0.53,respectively.The study suggests that different varieties of head cabbages have different nutritional advantages,and provides useful information to recommend the right head cabbages for consumers.

Leafy head formation of the progenies of transgenic plants of Chinese cabbage with exogenous auxin genes

The experiment was performed to evaluate the progenies of plant lines transgenic for auxin synthesis genes derived from Ri T-DNA. Four lines of the transgenic plants were selfcrossed and the foreign auxin genes in plants of T5 generation were confirmed by Southern hybridization. Two lines, D1232 and D1653, showed earlier folding of expanding leaves than untransformed line and therefore had early initiation of leaf y head. Leaf cuttings derived from plant of transgenic line D1653 produced more adventitious roots than the control whereas the cuttings from folding leaves had much more roots than rosette leaves at folding stage, and the cuttings from head leaves had more roots than rosette leaves at heading stage. It is demonstrated that early folding of transgenic leaf may be caused by the relatively higher concentration of auxin. These plant lines with auxin transgenes can be used for the study of hormonal regulation in differentiation and development of plant organs nd for the breeding of new varietywith rapid growth trait.