Waterlogging strongly affects agronomic performance of maize （Zea mays L.）. In order to investigate the suitable selection criteria of waterflooding tolerant genotypes, and identify the most susceptible stage and th...Waterlogging strongly affects agronomic performance of maize （Zea mays L.）. In order to investigate the suitable selection criteria of waterflooding tolerant genotypes, and identify the most susceptible stage and the best continuous treatment time to waterlogging, 20 common maize inbred lines were subjected to successive artificial waterflooding at seedling stage, and waterlogging tolerance coefficient （WTC） was used to screen waterflooding tolerant genotypes. In addition, peroxidase （POD） activities and malondialdehyde （MDA） contents were measured for 6 of 20 lines. The results showed that the second leaf stage （V2） was the most susceptible stage, and 6 d after waterflooding was the best continuous treatment time. Dry weight （DW） of both shoots and roots of all lines were significantly reduced at 6 d time-point of waterlogging, compared to control. POD activities and MDA contents were negatively and significantly correlated, and the correlation coefficient was -0.9686 （P 〈 0.0001）. According to the results, WTC of shoot DW can be used for practical screening as a suitable index, which is significantly different from control and waterlogged plants happened 6 d earlier. Furthermore, leaf chlorosis, MDA content and POD activities could also be used as reference index for material screening. The implications of the results for waterlogging-tolerant material screening and waterlogging-tolerant breeding have been discussed in maize.展开更多
In this study, SSH (Suppression Subtractive Hybridization) and cDNA microarray were used to identify genes associated with waterlogging response of maize roots. Mo17 and Hz32 are two maize inbred lines with differenti...In this study, SSH (Suppression Subtractive Hybridization) and cDNA microarray were used to identify genes associated with waterlogging response of maize roots. Mo17 and Hz32 are two maize inbred lines with differential tolerance to hypoxia. Seedlings of the inbred lines with two leaves were submerged in hypoxia buffer. SSH libraries were constructed with cDNA samples from roots. Both forward and reverse subtractions were performed for each inbred line, and 105 positive clones induced by hypoxia were selected by differential screening. The treated and control message RNA were hybridized with the cDNA microarray of Mo17, sequen-tially, 57 of 3-fold differentially expressed clones were obtained. A total of 162 positive clones were all sequenced. Bioinformatics analysis showed these positive clones represent 85 TUGs, including genes involved in several biochemistry pathways, such as glycolysis, protection, signal transduction, cell construction and energy metabolism and 41 EST with unknown function. Comparison between Mo17 and Hz32 indicates that genes related to hypoxia tolerance have different expression patterns in submerged roots. Several positive clones’ expression patterns were revealed by Northern or RT-PCR, and a new gene (Sicyp51), which may contribute to hy-poxia tolerance, was identified.展开更多
Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci （QTLs） associated with waterlogging tolerance at early stages of growth, survival rate （SR...Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci （QTLs） associated with waterlogging tolerance at early stages of growth, survival rate （SR）, germination rate index （GRI）, leaf chlorophyll content index （CCI）, root length index （RLI）, plant height index （PHI）, root dry weight index （RDWI）, shoot dry weight index （SDWI）, and total dry weight index （DWI） were assessed using the International Triticeae Mapping Initiative （ITMI） population W7984/Opata85. Significant and positive correlations were detected for all traits in this population except RLI. A total of 32 QTLs were associated with waterlogging tolerance on all chromosomes except 3A, 3D, 4B, 5A, 5D, 6A, and 6D. Some of the QTLs explained large proportions of the phenotypic variance. One of these is the QTL for GRI on 7A, which explained 23.92% of the phenotypic variation. Of them, 22 alleles from the synthetic hexaploid wheat W7984 contributed positively. These results suggested that synthetic hexaploid wheat W7984 is an important genetic resource for waterlogging tolerance in wheat. These alleles conferring waterlogging tolerance at early stages of growth in wheat could be utilized in wheat breeding for improving waterlogging tolerance.展开更多
Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reason...Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reasonable improvement programs.There were six germination traits investigated on combining ability and heritability using complete diallel crossing method designed for 30 combinations from those six cultivars and lines.The traits included relative root length,stem length,fresh weight per plant,survival rate,electrical conductivity,and vigor index.After flooding treatment,the six traits of parents and F1 were analyzed.The general combining ability（GCA） and special combining ability（SCA） of germination traits were analyzed using Griffing I method.Among 30 cross combinations,the GCA was significantly different among six waterlogging resistance traits.The SCA of these traits was significantly different except the SCA of electrical conductivity.As a representative trait of waterlogging tolerance in rapeseed,relative vigor index had the highest narrow heritability and relatively low broad heritability.The cultivars Zhongshuang 9 and P79 had higher tolerance potential to waterlogging stress.It can be concluded that combining ability and genetic effects of relative vigor index during germination stage could be used to identify the waterlogging tolerance of rapeseed in breeding program.展开更多
Effects of waterlogging on some physiological characters and relationship between waterlogging tolerance and some characters of their own were studied by using 12 varieties of wheat. Results showed waterlogging made t...Effects of waterlogging on some physiological characters and relationship between waterlogging tolerance and some characters of their own were studied by using 12 varieties of wheat. Results showed waterlogging made the content of malondialdehyde in flag leaf increase, made the root vigor, the content of chlorophyll, the net photosynthesis rate, the nitrate reductase activity, the relative water content of flag leaf decrease, the content of organic matter change obviously, and then the yield per plant declined. The correlations展开更多
The coding sequence of Vitreoscilla hemoglobin (vhb) was cloned with PCR technique from Vitreoscilla stercoraria Pringsheim. The plant expression vector with vhb gene under the control of CaMV 35S promoter was constru...The coding sequence of Vitreoscilla hemoglobin (vhb) was cloned with PCR technique from Vitreoscilla stercoraria Pringsheim. The plant expression vector with vhb gene under the control of CaMV 35S promoter was constructed and used in the transformation of Petunia hybrida Vilm by the Agrobacterium mediated procedure. The results of PCR amplification and Southern hybridization indicated that the vhb gene had been integrated into the petunia genome and the vhb gene expression had been detected by RT-PCR amplification. In hydroponic culture the transgenic petunias grew much better than non-transgenic controls. For further analysis of hypoxia tolerance of transgenic petunia, the petunia plants with vhb gene were submerged into liquid MS medium. The transgenic plants survived in hypoxic condition and grew out of the liquid surface in a few weeks, while non-transgenic plants were still submerged and suffocated in culture solution without ability to grow out of liquid medium in submersed culture for four to five weeks. The vhb gene transformed petunia plants had been planted and tested in a simulated flooding condition, and showed obvious tolerance to water-logging. It seen is that hemoglobin gene from Vitreoscilla might have the potential use in molecular breeding for the improvement of plant resistance to hypoxia and flooding.展开更多
Excess soil moisture induces hypoxic conditions and causes waterlogging injury in soybean [Glycine max (L.) Merr.]. This study investigated the mechanism underlying the development of waterlogging injury. Nine Japanes...Excess soil moisture induces hypoxic conditions and causes waterlogging injury in soybean [Glycine max (L.) Merr.]. This study investigated the mechanism underlying the development of waterlogging injury. Nine Japanese soybean cultivars with varying degrees of waterlogging tolerance were grown in a hydroponic system for 14 days under hypoxic conditions. Shoot and root biomasses and root hydraulic conductivity were measured at an early vegetative stage for plants under control and hypoxic conditions. Root morphological traits and intramembrane aquaporin proteins were also analyzed. The tolerance of each cultivar to field waterlogging was based on biomass changes induced by the hypoxia treatment. Root hydraulic conductivity responses to hypoxia were associated with changes in total dry weight, leaf dry weight, and leaf area. The effects of hypoxic conditions on root hydraulic conductivity were also represented by the changes in root morphology, such as total root length, thick-root length, and number of root tips. Additionally, a 32.3 kDa aquaporin-like protein seemed to regulate root hydraulic conductivity. Our results from a hydroponic culture suggest that the soybean cultivar-specific responses to hypoxic conditions in the rhizosphere reflect fluctuations in hydraulic conductivity related to root morphological or qualitative changes.展开更多
Maize is one of the most important food crops in the world.With the global warming,waterlogging stress has become an important abiotic stress factor that affects crop growth,including maize.Waterlogging seriously affe...Maize is one of the most important food crops in the world.With the global warming,waterlogging stress has become an important abiotic stress factor that affects crop growth,including maize.Waterlogging seriously affects 10%of the arable land and can lead to a 15%-80%reduction in crop yield[1].In this study,115 inbred line materials commonly used in spring maize planting areas in the Jianghan Plain,Hubei,and maize inbred line B73 with complete genome information,were collected and stressed by waterlogging for two weeks in the seven-leaf and one-heart stage,and the survival rate was statistically compared and analyzed,aiming to screen germplasms with strong waterlogging tolerance for the genetic improvement of waterlogging tolerance of Hubei maize lines.展开更多
基金supported by the Natural Science Foundation of Hubei Province, China (2008CDB079)the National High Technology Research and Development Program of China (863 Program,2006AA100103)
文摘Waterlogging strongly affects agronomic performance of maize （Zea mays L.）. In order to investigate the suitable selection criteria of waterflooding tolerant genotypes, and identify the most susceptible stage and the best continuous treatment time to waterlogging, 20 common maize inbred lines were subjected to successive artificial waterflooding at seedling stage, and waterlogging tolerance coefficient （WTC） was used to screen waterflooding tolerant genotypes. In addition, peroxidase （POD） activities and malondialdehyde （MDA） contents were measured for 6 of 20 lines. The results showed that the second leaf stage （V2） was the most susceptible stage, and 6 d after waterflooding was the best continuous treatment time. Dry weight （DW） of both shoots and roots of all lines were significantly reduced at 6 d time-point of waterlogging, compared to control. POD activities and MDA contents were negatively and significantly correlated, and the correlation coefficient was -0.9686 （P 〈 0.0001）. According to the results, WTC of shoot DW can be used for practical screening as a suitable index, which is significantly different from control and waterlogged plants happened 6 d earlier. Furthermore, leaf chlorosis, MDA content and POD activities could also be used as reference index for material screening. The implications of the results for waterlogging-tolerant material screening and waterlogging-tolerant breeding have been discussed in maize.
基金This work was supported by the National Natu-ral Science Foundation of China(Grant No.30370886),Hubei Natural Science Fund(Grant No.2003ABA094)the Doctoral Progr am F oundation of the Ministry of Education(Grant No.20030504021).
文摘In this study, SSH (Suppression Subtractive Hybridization) and cDNA microarray were used to identify genes associated with waterlogging response of maize roots. Mo17 and Hz32 are two maize inbred lines with differential tolerance to hypoxia. Seedlings of the inbred lines with two leaves were submerged in hypoxia buffer. SSH libraries were constructed with cDNA samples from roots. Both forward and reverse subtractions were performed for each inbred line, and 105 positive clones induced by hypoxia were selected by differential screening. The treated and control message RNA were hybridized with the cDNA microarray of Mo17, sequen-tially, 57 of 3-fold differentially expressed clones were obtained. A total of 162 positive clones were all sequenced. Bioinformatics analysis showed these positive clones represent 85 TUGs, including genes involved in several biochemistry pathways, such as glycolysis, protection, signal transduction, cell construction and energy metabolism and 41 EST with unknown function. Comparison between Mo17 and Hz32 indicates that genes related to hypoxia tolerance have different expression patterns in submerged roots. Several positive clones’ expression patterns were revealed by Northern or RT-PCR, and a new gene (Sicyp51), which may contribute to hy-poxia tolerance, was identified.
基金supported by the National Basic Research Program of China (2011CB100100)the National High-Tech R&D Program of China (2011AA100103)the National Natural Science Foundation of China (31230053 and 31171556)
文摘Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci （QTLs） associated with waterlogging tolerance at early stages of growth, survival rate （SR）, germination rate index （GRI）, leaf chlorophyll content index （CCI）, root length index （RLI）, plant height index （PHI）, root dry weight index （RDWI）, shoot dry weight index （SDWI）, and total dry weight index （DWI） were assessed using the International Triticeae Mapping Initiative （ITMI） population W7984/Opata85. Significant and positive correlations were detected for all traits in this population except RLI. A total of 32 QTLs were associated with waterlogging tolerance on all chromosomes except 3A, 3D, 4B, 5A, 5D, 6A, and 6D. Some of the QTLs explained large proportions of the phenotypic variance. One of these is the QTL for GRI on 7A, which explained 23.92% of the phenotypic variation. Of them, 22 alleles from the synthetic hexaploid wheat W7984 contributed positively. These results suggested that synthetic hexaploid wheat W7984 is an important genetic resource for waterlogging tolerance in wheat. These alleles conferring waterlogging tolerance at early stages of growth in wheat could be utilized in wheat breeding for improving waterlogging tolerance.
基金supported by the National High-Tech Research and Development Program of China (863 Program,2006AA10Z1C2)the Key Technologies R&D Program of China during the 10th Five-Year Plan period (2009BADA8B01,2110BAD01B09)the Natural Science Foundation of Hubei Province,China(2009CDA089)
文摘Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reasonable improvement programs.There were six germination traits investigated on combining ability and heritability using complete diallel crossing method designed for 30 combinations from those six cultivars and lines.The traits included relative root length,stem length,fresh weight per plant,survival rate,electrical conductivity,and vigor index.After flooding treatment,the six traits of parents and F1 were analyzed.The general combining ability（GCA） and special combining ability（SCA） of germination traits were analyzed using Griffing I method.Among 30 cross combinations,the GCA was significantly different among six waterlogging resistance traits.The SCA of these traits was significantly different except the SCA of electrical conductivity.As a representative trait of waterlogging tolerance in rapeseed,relative vigor index had the highest narrow heritability and relatively low broad heritability.The cultivars Zhongshuang 9 and P79 had higher tolerance potential to waterlogging stress.It can be concluded that combining ability and genetic effects of relative vigor index during germination stage could be used to identify the waterlogging tolerance of rapeseed in breeding program.
文摘Effects of waterlogging on some physiological characters and relationship between waterlogging tolerance and some characters of their own were studied by using 12 varieties of wheat. Results showed waterlogging made the content of malondialdehyde in flag leaf increase, made the root vigor, the content of chlorophyll, the net photosynthesis rate, the nitrate reductase activity, the relative water content of flag leaf decrease, the content of organic matter change obviously, and then the yield per plant declined. The correlations
文摘The coding sequence of Vitreoscilla hemoglobin (vhb) was cloned with PCR technique from Vitreoscilla stercoraria Pringsheim. The plant expression vector with vhb gene under the control of CaMV 35S promoter was constructed and used in the transformation of Petunia hybrida Vilm by the Agrobacterium mediated procedure. The results of PCR amplification and Southern hybridization indicated that the vhb gene had been integrated into the petunia genome and the vhb gene expression had been detected by RT-PCR amplification. In hydroponic culture the transgenic petunias grew much better than non-transgenic controls. For further analysis of hypoxia tolerance of transgenic petunia, the petunia plants with vhb gene were submerged into liquid MS medium. The transgenic plants survived in hypoxic condition and grew out of the liquid surface in a few weeks, while non-transgenic plants were still submerged and suffocated in culture solution without ability to grow out of liquid medium in submersed culture for four to five weeks. The vhb gene transformed petunia plants had been planted and tested in a simulated flooding condition, and showed obvious tolerance to water-logging. It seen is that hemoglobin gene from Vitreoscilla might have the potential use in molecular breeding for the improvement of plant resistance to hypoxia and flooding.
文摘Excess soil moisture induces hypoxic conditions and causes waterlogging injury in soybean [Glycine max (L.) Merr.]. This study investigated the mechanism underlying the development of waterlogging injury. Nine Japanese soybean cultivars with varying degrees of waterlogging tolerance were grown in a hydroponic system for 14 days under hypoxic conditions. Shoot and root biomasses and root hydraulic conductivity were measured at an early vegetative stage for plants under control and hypoxic conditions. Root morphological traits and intramembrane aquaporin proteins were also analyzed. The tolerance of each cultivar to field waterlogging was based on biomass changes induced by the hypoxia treatment. Root hydraulic conductivity responses to hypoxia were associated with changes in total dry weight, leaf dry weight, and leaf area. The effects of hypoxic conditions on root hydraulic conductivity were also represented by the changes in root morphology, such as total root length, thick-root length, and number of root tips. Additionally, a 32.3 kDa aquaporin-like protein seemed to regulate root hydraulic conductivity. Our results from a hydroponic culture suggest that the soybean cultivar-specific responses to hypoxic conditions in the rhizosphere reflect fluctuations in hydraulic conductivity related to root morphological or qualitative changes.
基金"Seven Major Crop Breeding"Special Project(2018YFD01-00102)。
文摘Maize is one of the most important food crops in the world.With the global warming,waterlogging stress has become an important abiotic stress factor that affects crop growth,including maize.Waterlogging seriously affects 10%of the arable land and can lead to a 15%-80%reduction in crop yield[1].In this study,115 inbred line materials commonly used in spring maize planting areas in the Jianghan Plain,Hubei,and maize inbred line B73 with complete genome information,were collected and stressed by waterlogging for two weeks in the seven-leaf and one-heart stage,and the survival rate was statistically compared and analyzed,aiming to screen germplasms with strong waterlogging tolerance for the genetic improvement of waterlogging tolerance of Hubei maize lines.
