Entity

Time filter

Source Type


Lv X.,China Agricultural University | Lv X.,CAS Institute of Zoology | Guo Y.,National Agricultural Technology Extension and Service Center | Shi D.,China Agricultural University
Reproductive Biology | Year: 2012

The effects of the two sterilants, quinestrol (QE) and levonorgestrel (LNG) on serum prolactin (PRL) level in lactating Mongolian gerbils and reproductive parameters of their offspring were examined in the study. Both sterilants increased the serum PRL level in lactating gerbils. The body weight as well as weights of the ovary, testis, epididymides, and seminal vesicles were lower, whereas that of the uterus was higher in the pups originating from QEtreated mothers in comparison to controls. Histological ovarian sections of the offspring from QE-treated mothers contained only growing follicles, whereas their uterine sections showed a thinner endometrium, thicker myometrium, and greater epithelial-cell height than in controls. The histometrical testis characteristics as well as sperm concentration and motility of male pups from QE-treated mothers were lower compared to those of the control group. The serum gonadotropin levels of female pups from mothers treated with QE were lower, whereas the serum estradiol (E2) and progesterone (P4) levels were higher than in control gerbils. In contrast, serum gonadotropin and testosterone (T) levels of male pups from QE-treated mothers were lower compared to controls. LNG did not affect the examined parameters of the offspring. The offspring from QE-treated mothers was infertile, whereas the offspring from LNG-treated mothers was fertile. In summary, QE and LNG have a stimulatory effect on PRL level in lactating gerbils. It also appears that QE administered via milk to mothers affects reproductive processes of their offspring. © 2012 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn.


Lv X.,China Agricultural University | Guo Y.,National Agricultural Technology Extension and Service Center | Shi D.,China Agricultural University
Theriogenology | Year: 2012

Quinestrol, a synthetic estrogen with marked estrogenic effects and prolonged activity, has potential as a contraceptive for Mongolian gerbils. The objective of this study was to describe the effects of quinestrol on reproductive hormone expression, secretion, and receptor levels in female Mongolian gerbils. Serum and pituitary concentrations of follicle stimulating hormone (FSH) and luteinizing hormone (LH) were decreased, whereas serum concentrations of estradiol (E2) and progesterone (P4) were increased after quinestrol treatment; the effects were both time- and dose-dependent. Furthermore, quinestrol downregulated expression of FSHβ and LHβ mRNA in the pituitary gland, as well as FSH receptor (FSHR) and estrogen receptor (ER) β in the ovary. However, it up-regulated mRNA expression levels of ERα and progesterone receptor (PR) in the pituitary gland and uterus, as well as mRNA for LH receptor (LHR) and PR in the ovary (these effects were time- and dose-dependent). In contrast, quinestrol had no significant effects on the mRNA expression levels of ERα in the ovary, or the gonadotropin α (GtHα) subunit in the pituitary gland. We inferred that quinestrol impaired synthesis and secretion of FSH and LH and that the predominant ER subtype in the pituitary gland of Mongolian gerbils may be ERα. Overall, quinestrol disrupted reproductive hormone receptor expression at the mRNA level in the pituitary-gonadal axis of the Mongolian gerbil. © 2012 Elsevier Inc.


Bao Y.X.,Nanjing University of Information Science and Technology | Huang J.Y.,Nanjing University of Information Science and Technology | Xie X.J.,Nanjing University of Information Science and Technology | Lu M.H.,National Agricultural Technology Extension and Service Center
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2013

Based on the daily reanalyzed meteorological dataset of the National Center of Environment Predicting (NCEP) in USA and the pentadly lighting catches of brown planthoppers (BPH) in China, in this paper, the temporal and spatial relationship between the selected monsoon index and the immigrations of BPH was investigated to explore the influence of monsoon advancing, retreating and conversion on the immigrations of BPH in China. The results showed as follows: (1) The middle ten days and the last ten days of March in a year is a conversing period from the north monsoon to southwest monsoon and the first large-scale migration northward of BPH's populations occurs in the first ten days of April after the beginning of the southwest monsoon. The main landing regions of BPH's populations in this large-scale migration northward are the rice-growing regions in the South and the Southwestern China. Then, the BPH's populations migrate to the other northern parts subsequently. (2) From the middle ten days of June to the middle ten days of August in a year, the south monsoon index reach its maximum of the positive values while the migrations northward of BPH occur most frequently, the populations land in the all four main rice-growing regions, the peaks and landing heads of BPH's immigration northward amount to the summit. (3) From the last ten days period of August to the middle ten days of September in a year is a conversing period from the south monsoon to the north monsoon and it is the ending period of BPH's immigration northward and the beginning period of the immigration southward. The first large-scale migration southward of BPH' s populations occurs in this period and the main landing regions are the rice-growing regions between the Yangtze River and the Huaihe River and the rice-growing regions between the Yangtze River and the Nanling Mountain. (4) From the last ten days of September to the middle ten days of October is the strengthening period of the north monsoon and the weakening period of the south monsoon and it is the peak period of BPH's immigration southward of all rice-growing regions. (5) In the last tendays of October, the south monsoon begins the evacuating from the mainland of China and the north monsoon begins controlling the mainland and the ending dates of BPH's immigrations appear in each rice-growing region successively from north to south. (6) In the years of BPH's abnormal occurrence, the sooner or later advancing northward of the southwest monsoon decided on the beginning dates of BPH's immigration and the expanding southward some time or later of the north monsoon determined the ending dates of BPH's immigration coming earlier or later. (7) The beginning date of BPH'simmigration falled behind the change of the southwest monsoon and the ending date of immigration lagged behind the change of the north monsoon and their delaying times were 5 to 15 days.


Bao Y.-X.,Nanjing University of Information Science and Technology | Ding W.-W.,Nanjing University of Information Science and Technology | Xie X.-J.,Nanjing University of Information Science and Technology | Lan P.,Nanjing University of Information Science and Technology | Lu M.-H.,National Agricultural Technology Extension and Service Center
Journal of Tropical Meteorology | Year: 2014

In order to clarify the statistical pattern by which landfalling strong tropical cyclones (LSTCs) influenced the catastrophic migrations of rice brown planthopper (BPH), Nilaparvata lugens (stål) in China, the data of the LSTCs in China and the lighting catches of BPH that covered the main Chinese rice-growing regions from 1979 to 2008 were collected and analyzed in this work with the assistance of ArcGIS9.3, a software of geographic information system. The results were as follows: (1) In China, there were 220 strong tropical cyclones that passed the main rice-growing regions and 466 great events of BPH's immigration in the 30 years from 1979 to 2008. 73 of them resulted in the occurrence of BPH's catastrphic migration (CM) events directly and 147 of them produced indirect effect on the migrations. (2) The number of the LSTCs was variable in different years during 1979 to 2008 and their influence was not the same in the BPH's northward and southward migrations in the years. In the 30 years, the LSTCs brought more obvious influence on the migrations in 1980, 1981, 2005, 2006 and 2007. The influence was the most obvious in 2007 and all of the 7 LSTCs produced remarkable impact on the CMs of BPH's populations. The effect of the LSTCs on the northward immigration of BPH's populations was the most serious in 2006 and the influence on the southward immigration was the most remarkable in 2005. (3) In these years, the most of LSTCs occurred in July, August and September and great events of BPH's immigration occurred most frequently in the same months. The LSTCs played a more important role on the CM of BPH's populations in the three months than in other months. (4) The analysis on the spatial distribution of the LSTCs and BPH's immigration events for the different provinces showed that the BPH's migrations in the main rice-growing regions of the Southeastern China were influenced by the LSTCs and the impact was different with the change of their spatial probability distribution during their passages. The most serious influence of the LSTCs on the BPH's migrations occurred in Guangdong and Fujian provinces. (5)The statistical results indicated that a suitable insect source is an indispensable condition of the CMs of BPH when a LSTC influenced a rice-growing region.


Yang F.,National Agricultural Technology Extension and Service Center | Dong Y.,National Agricultural Technology Extension and Service Center | Xu M.-G.,Chinese Academy of Agricultural Sciences | Bao Y.-X.,Chinese Academy of Agricultural Sciences
Chinese Journal of Applied Ecology | Year: 2012

Based on the data from 94 experiments of straw returning in Anhui, Jiangxi, Hunan, Hubei, Guangxi, Sichuan, and Chongqing, and by using mathematic modeling approach, this paper evaluated the effects of straw returning on the soil fertility and crop yield in southern China. Obvious regional differences were observed in the soil fertility index (SFI) and crop yield response. In study area, the croplands with the SFI of Grade III and Grade IV were predominant, occupying 69.1% and 21.3% of the total, respectively. Averagely, straw returning increased the SFI and crop yield by 6.8% and 4.4%, respectively, as compared with the control (no straw returning). The SFI was significantly linearly correlated with rice yield, and could well reflect the integrated soil fertility in study area. At present, straw returning with decomposing agent added is one of the most important measures to improve the integrated soil fertility in southern China, which should be widely popularized.

Discover hidden collaborations