No abstract

Few attempts have been made to study the alleviating effects of signal molecules on zoysiagrass ( Zoysia japonica ) under drought stress. Calcium chloride has been shown to ameliorate the adverse effects of drought stress on many plants. It is necessary to investigate how to enhance drought tolerance of zoysiagrass using calcium chloride. The study elucidated the effects of calcium chloride on zoysiagrass under drought conditions by investigating the following parameters: biomass, chlorophyll (Chl) content, net photosynthetic rate (Pn), chlorophyll fluorescence, antioxidant enzymes, proline content, and malondialdehyde (MDA) content. Experimental conditions consisted of an aqueous CaCl2 solution at 5, 10, and 20 mM sprayed on zoysiagrass leaves for 3 d, following by an inducement of drought conditions by withholding water for 16 d. Under drought conditions, all CaCl2 pretreatments were found to increase the above-ground fresh biomass, as well as below-ground fresh and dry biomass. The resulting Chl (a, b, a+b) contents of the 5 and 10 mM CaCl2 pretreatment groups were higher than those of the control. In the later stages of drought conditions, the chlorophyll fluorescence parameter Fv/Fm was higher in leaves treated with 10 mM CaCl2 than in the leaves of the other two treatment groups. Zoysiagrass pretreated with 10 mM CaCl2 possessed both the maximum observed Pn and antioxidant enzyme activities. Meanwhile, lower MDA and proline contents were recorded in the plants pretreated with 5 and 10 mM CaCl2 under drought conditions. As a whole, the drought tolerance of zoysiagrass was improved to some extent by the application of a moderate calcium concentration.

The study was to assess the associations of prepregnancy body mass index (BMI) and gestational weight gain (GWG) with pregnancy outcomes. This was a retrospective analysis of 2973 nulliparous women who delivered single live babies. Prepregnancy BMI was categorized as underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2) or overweight/obese (≥25.0 kg/m2). GWG was categorized as inadequate, adequate or excessive. 567 (19.1%) women were overweight/obese, and 1600 (53.8%) exhibited excessive GWG. Compared with women of normal weight, overweight/obese women had a higher incidence of cesarean section (odds ratio, 95% confidence interval: 2.02, 1.59–2.56), postpartum hemorrhage (1.50, 1.05–2.14), preterm delivery (2.51, 1.83–3.45), preterm premature rupture of membranes (2.11, 1.32–3.38), gestational diabetes mellitus (2.04, 1.65–2.53), gestational hypertension (7.68, 4.21–14.00), preeclampsia (1.98, 1.18–3.33) and small for gestational age (2.81, 1.21–6.54). Compared with adequate GWG, excessive GWG increased the incidence of cesarean section (2.02, 1.59–2.56), preterm delivery (1.48, 1.05–2.71), preeclampsia (1.78, 1.34–4.27) and macrosomia (2.61, 1.61–4.25), and reduced the incidence of gestational diabetes mellitus (0.75, 0.62–0.92). High prepregnancy BMI and excessive GWG in nulliparous Chinese women are associated with adverse pregnancy outcomes. Weight control before and during pregnancy could reduce the complications of pregnancy.