Critical period for weed control in direct seeded red pepper (Capsicum annum L.)     

NIHAT TURSUN  IRFAN ERSIN AKINCI  AHMET ULUDAG  ZULEYHA PAMUKOGLU  DOGAN GOZCU 《Weed Biology and Management》2012,12(2):109-115

Direct seeded red pepper is a cash crop in Kahramanmara? province of Turkey as well as some other nearby provinces. Weeds are a major constraint in red pepper production. Field studies were conducted to determine critical period for weed control (CPWC) in direct seeded spice pepper in Kahramanmara?, in 2008 and 2009. The CPWC in red pepper based on a 2.5%, 5% and 10% acceptable yield loss (AYL) was calculated by fitting logistic and Gompertz equations to relative yield data. The CPWC in red pepper was determined from 0 to 1087 growing degree days (GDD) in 2008 and from 109 to 796 GDD in 2009 for 10% AYL after crop emergence in red pepper. For 2.5–5% AYL, the CPWC starts with germination and lasts until harvest. Direct seeded red pepper is very vulnerable to weed competition and weed control programs for direct seeded spice pepper in Turkey should include pre‐emergence and residual herbicides.  相似文献   

Quantification of momilactone B in rice hulls and the phytotoxic potential of rice extracts on the seed germination of Alisma plantago‐aquatica     

HUSREV MENNAN  MATHIEU NGOUAJIO  MEVLUT SAHIN  DOGAN ISIK  EMINE KAYA ALTOP 《Weed Biology and Management》2012,12(1):29-39

The occurrence of herbicide‐resistant weeds has boosted interest in the use of crop allelopathy as a potential alternative to herbicides for weed control in rice (Oryza sativa). The phytotoxic compounds that are released by rice could help to enhance its competitive ability and improve weed management. This study aimed to screen rice genotypes for phytotoxic activity, quantify the amount of momilactone B in various rice tissues, and identify the potential parental lines for quantitative trait locus analysis. Therefore, a total of 41 cultivars from germplasm collections was evaluated for their effects. Significant differences were found among the rice cultivars in their ability to reduce the germination, root growth, and root dry weight accumulation of Alisma plantago‐aquatica. The leaf extract was the most inhibitory to germination. Out of the five cultivars that were tested, momilactone B was detected in four of them: Marateli, Kizilirmak, Karadeniz, and Kiziltan. Karadeniz and Kiziltan were identified as the rice cultivars with a high momilactone B content in the tissues and therefore they could be used in breeding programs to enhance the phytotoxic potential of rice. The development of a rice cultivar with proven allelopathic characteristics could provide an environmentally friendly and low‐cost approach for the control of A. plantago‐aquatica.  相似文献   

Interrelationships Between Apoptosis and Fertility in Bull Sperm     

Sule DOGAN  Melissa C. MASON  Aruna GOVINDARAJU  Lauren BELSER  Abdullah KAYA  John STOKES  Dennis ROWE  Erdogan MEMILI 《The Journal of reproduction and development》2013,59(1):18-26

Male fertility, the ability of sperm to fertilize and activate the egg and support early embryogenesis, is vital for mammalian reproduction. Despite producing adequate numbers of sperm with normal motility and morphology, some males suffer from low fertility whose molecular mechanisms are not known. The objective was to determine apoptosis in sperm from high and low fertility bulls and its relationship with male fertility. DNA damage, phosphatidylserine (PS) translocation, and expression of pro- and anti-apoptotic proteins (BAX and BCL-2) in the sperm were determined using TUNEL, Annexin V, and immunoblotting approaches, respectively. Amounts of apoptotic spermatozoa were 2.86 (± 1.31) and 3.00 (± 0.96) in high and low fertility bulls, respectively (P=0.548), and were not correlated with fertility. There was a negative correlation between early necrotic spermatozoa and viable spermatozoa (r = –0.99, P<0.0001). Fertility scores were correlated with live spermatozoa detected by eosin-nigrosin test and necrotic spermatozoa determined via flow cytometry (r = –0.49, P<0.006 and r = –0.266, P<0.0113, respectively). BAX level was higher in low fertile group than high fertile group; however, this difference was not statistically significant due to the variations of bull samples (Bull 1–3 vs. Bull 4–5) in low fertile group (P<0.283). BCL-2 was not detectable in any of the sperm samples. The results shed light onto molecular and cellular underpinnings of male fertility.  相似文献