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With Yunyan 87 as an experimental material, the effects of different transplanting dates on the growth and development of tobacco plants and the yield and quality of cured tobacco leaves were studied in Lingbao City, Sanmenxia City. With the postponement of transplanting date, the growth period in field was prolonged , and the plant height and leaf area both increased at first and decreased then. TMV, weather fleck and brown spot all showed an incidence and a disease index decreased with the postponement of transplanting date. The total sugar and reducing sugar contents of the cured tobacco leaves from the upper and middle part increased at first and decreased then with the postponement of transplanting date. The main nitrogenous compounds decreased at first and increased then. The economic traits and leaf class were on the decrease [ABSTRACT FROM AUTHOR]

Abstract??Rehmannia glutinosaseedlings were pretreated with choline chloride (CC) in concentrations of 0, 0.7, 2.1 and 3.5?mM, and then subjected to drought and rewatering treatment to study the effects of CC on the generation of reactive oxygen species (O2?, H2O2), lipid peroxidation, proline accumulation, water status and photosynthesis. The results showed that pretreatment with CC alleviated the inhibition of SOD and APX activity caused by drought stress, and therefore, the rate of O2?production and H2O2concentration were reduced and lipid peroxidation decreased in pretreated plants. CC pretreatment also accelerated accumulation of proline, maintained higher ?w and RWC, deferred leaf water loss during drought stress and retarded the drop in proline concentration after rewatering. Consequently, drought-induced decreases in Fm/F0, Fv/Fm, ?PS2, qP, and A and increase in qNPwere inhibited and the recovery of photosynthesis after rewatering was quicker in pretreated plants. Although differences in Fv/Fm, ?PS2and qPbetween treatments were not significant, there was a general trend that the effects of CC increased with the rise of its concentrations. The data suggested that 2.1?mM of CC be suitable for alleviating lipid peroxidation, promoting proline accumulation, retarding leaf water loss and improving photosynthesis ofR. glutinosaseedlings under drought stress. [ABSTRACT FROM AUTHOR]