Two japonica rice varieties, Longjing 20 （more tillers and curved panicle type, MCP） and Longjing 21 （few tillers and half erect panicle type, FEP）, were used to study the effects of row-spacing on canopy structur...Two japonica rice varieties, Longjing 20 （more tillers and curved panicle type, MCP） and Longjing 21 （few tillers and half erect panicle type, FEP）, were used to study the effects of row-spacing on canopy structure, morphological characteristics and yield. The results showed that the percentage of productive tiller reduced first, and increased afterwards as row-spacing increasing. The relationship between row spacing and the percentage of productive tiller fitted a quadratic regression. The effects of row spacing on leaf area index （LAI） at later tillering stage and the highest stem number per square meter also followed a quadratic regression relationship with increasing first and then reducing. The effects of row-spacing on primary branch were larger than the secondary branch in Longjing 20. However, the trend in Longjing 21 was opposite. The relationship between row spacing and seed setting rate of the secondary branch or panicle was negatively correlated. An extreme significant negative correlation was obtained between seed setting rate of secondary branch in Longjing 20. There was no significant positive correlation between row-spacing and yield in Longjing 20 （R2=0.68）. However, the negative correlation between row-spacing and yield of Longjing 21 was extremely significant （R2=–0.96＊＊）. The canopy structure of MCP was more sensitive to row-spacing. The positive correlation between row spacing and the length of the flag leaf （R2=0.89＊＊）, the width of the flag leaf （R2=0.85＊）, the length of the last internode （R2=0.85＊）, the length of the last 2nd internode （R2=0.96＊＊） or the length of the panicle （R2=0.91＊＊） was significant or extremely significant in Longjing 20, but not in Longjing 21. The wider row-spacing promoted the accumulation of the dry matter of panicle, stem and leaf and the yield formation in MCP. The best row-spacing in Longjing 20 was 30 cm. For Longjing 21, the narrower row-spacing was better. The best row-spacing of it was 21 cm. These results suggested that improved the population environment of MCP or the utilization of the free space in the field of FEP could be reached either by wider row-spacing or narrow row-spacing.展开更多
Improved yield potential is the goal of barley domestication and cultivation.During this process,two-and six-rowed barley types emerged and have been utilised in breeding and production.The six-rowed type could produc...Improved yield potential is the goal of barley domestication and cultivation.During this process,two-and six-rowed barley types emerged and have been utilised in breeding and production.The six-rowed type could produce three times as many grains as its ancestral two-rowed forms,thus dominating barley cultivation for thousands of years.The deficiens form of the two-rowed type,characterised by extremely suppressed lateral spikelets,has gained dominance over the past few decades in barley-growing regions worldwide.We hypothesised that the absence of lateral spikelets in deficiens barley affects spike architecture and spike-related traits,contributing to its superior yield potential of deficiens barley cultivation.Currently,a deficiens barley variety,RGT Planet,is the most popular barley variety in the world.In this study,we used two F_(2) populations derived from crossing RGT Planet with two canonical two-rowed barley and identified the functional allele Vrs1.t1 associated with deficiens morphology.We observed that the Vrs1.t1 allele may contribute to high yield potential by optimising spike architecture through increased spikelet length,grain number,and grain size.Phylogenetic analysis suggests that the deficiens mutation was likely present from the early stages of barley cultivation in the Fertile Crescent and spread to Ethiopia and beyond with agricultural expansion.We conclude that the ancient deficiens allele Vrs1.t1 has been a critical driver for the recent success of modern barley improvement by optimising spike architecture.展开更多
A row-type mutant of barley named poly-row-and-branched spike （prbs） was previously obtained from a two-rowed cultivar Pudamai-2 after treated by inflorescence soaking in maize total DNA solution. The mutant produce...A row-type mutant of barley named poly-row-and-branched spike （prbs） was previously obtained from a two-rowed cultivar Pudamai-2 after treated by inflorescence soaking in maize total DNA solution. The mutant produces branched spikes with irregular multiple rows. Genetic analysis indicated that the mutant phenotype was caused by a recessive gene prbs, and the PRBS locus had a recessive epistatic effect on an independent locus （denoted as Vrsx） conferring the variation of two-rowed spike vs. six-rowed spike. This study aimed to map PRBS as well as Vrsx using simple sequence repeats （SSR） markers. We developed an F2 population from a cross between the prbs mutant and a six-rowed cultivar Putianwudu for the gene mapping. As the two target loci interacted to result in a segregation ratio of two-rowed type：six-rowed type：prbs=9：3：4 in the population, we adopted a special strategy to map the two loci. PRBS was mapped between SSR markers HvLTPPB and Bmag0508A on the short arm of chromosome 3H, with distances of 24.7 and 14.3 cM to the two markers, respectively. Vrsx was mapped between SSR markers Bmag0125 and Bmag0378 on chromosome 2H, with distances of 6.9 and 15.3 cM to the two markers, respectively. This suggests that Vrsx should be the known locus Vrs1, which predominantly controls row-type variation in barley cultivars, and PRBS is a new locus related to the row type of spikes in barley.展开更多
基金Supported by the National Key Technology R&D Program (2007BAD65B01-4)Science and Technology Development Plan of Heilongjiang Province in China (GB06B104-1-5)Key Technology R&D Program of Heilongjiang Province in China (GA09B102-3)
文摘Two japonica rice varieties, Longjing 20 （more tillers and curved panicle type, MCP） and Longjing 21 （few tillers and half erect panicle type, FEP）, were used to study the effects of row-spacing on canopy structure, morphological characteristics and yield. The results showed that the percentage of productive tiller reduced first, and increased afterwards as row-spacing increasing. The relationship between row spacing and the percentage of productive tiller fitted a quadratic regression. The effects of row spacing on leaf area index （LAI） at later tillering stage and the highest stem number per square meter also followed a quadratic regression relationship with increasing first and then reducing. The effects of row-spacing on primary branch were larger than the secondary branch in Longjing 20. However, the trend in Longjing 21 was opposite. The relationship between row spacing and seed setting rate of the secondary branch or panicle was negatively correlated. An extreme significant negative correlation was obtained between seed setting rate of secondary branch in Longjing 20. There was no significant positive correlation between row-spacing and yield in Longjing 20 （R2=0.68）. However, the negative correlation between row-spacing and yield of Longjing 21 was extremely significant （R2=–0.96＊＊）. The canopy structure of MCP was more sensitive to row-spacing. The positive correlation between row spacing and the length of the flag leaf （R2=0.89＊＊）, the width of the flag leaf （R2=0.85＊）, the length of the last internode （R2=0.85＊）, the length of the last 2nd internode （R2=0.96＊＊） or the length of the panicle （R2=0.91＊＊） was significant or extremely significant in Longjing 20, but not in Longjing 21. The wider row-spacing promoted the accumulation of the dry matter of panicle, stem and leaf and the yield formation in MCP. The best row-spacing in Longjing 20 was 30 cm. For Longjing 21, the narrower row-spacing was better. The best row-spacing of it was 21 cm. These results suggested that improved the population environment of MCP or the utilization of the free space in the field of FEP could be reached either by wider row-spacing or narrow row-spacing.
基金Funding for this research was provided by the Australia Grain Research and Development Corporation(9176507)the Western Crop Genetics Alliance.Jingye Cheng thanks The University of Tasmania,Australia for the scholarship(495802)。
文摘Improved yield potential is the goal of barley domestication and cultivation.During this process,two-and six-rowed barley types emerged and have been utilised in breeding and production.The six-rowed type could produce three times as many grains as its ancestral two-rowed forms,thus dominating barley cultivation for thousands of years.The deficiens form of the two-rowed type,characterised by extremely suppressed lateral spikelets,has gained dominance over the past few decades in barley-growing regions worldwide.We hypothesised that the absence of lateral spikelets in deficiens barley affects spike architecture and spike-related traits,contributing to its superior yield potential of deficiens barley cultivation.Currently,a deficiens barley variety,RGT Planet,is the most popular barley variety in the world.In this study,we used two F_(2) populations derived from crossing RGT Planet with two canonical two-rowed barley and identified the functional allele Vrs1.t1 associated with deficiens morphology.We observed that the Vrs1.t1 allele may contribute to high yield potential by optimising spike architecture through increased spikelet length,grain number,and grain size.Phylogenetic analysis suggests that the deficiens mutation was likely present from the early stages of barley cultivation in the Fertile Crescent and spread to Ethiopia and beyond with agricultural expansion.We conclude that the ancient deficiens allele Vrs1.t1 has been a critical driver for the recent success of modern barley improvement by optimising spike architecture.
基金supported by the Natural Science Foundation of Fujian Province, China (B0310012)the Education Department of Fujian Province, China (JA09079)the Postdoctoral Research Fund of Human Resources Office of Fujian Province, China (80222)
文摘A row-type mutant of barley named poly-row-and-branched spike （prbs） was previously obtained from a two-rowed cultivar Pudamai-2 after treated by inflorescence soaking in maize total DNA solution. The mutant produces branched spikes with irregular multiple rows. Genetic analysis indicated that the mutant phenotype was caused by a recessive gene prbs, and the PRBS locus had a recessive epistatic effect on an independent locus （denoted as Vrsx） conferring the variation of two-rowed spike vs. six-rowed spike. This study aimed to map PRBS as well as Vrsx using simple sequence repeats （SSR） markers. We developed an F2 population from a cross between the prbs mutant and a six-rowed cultivar Putianwudu for the gene mapping. As the two target loci interacted to result in a segregation ratio of two-rowed type：six-rowed type：prbs=9：3：4 in the population, we adopted a special strategy to map the two loci. PRBS was mapped between SSR markers HvLTPPB and Bmag0508A on the short arm of chromosome 3H, with distances of 24.7 and 14.3 cM to the two markers, respectively. Vrsx was mapped between SSR markers Bmag0125 and Bmag0378 on chromosome 2H, with distances of 6.9 and 15.3 cM to the two markers, respectively. This suggests that Vrsx should be the known locus Vrs1, which predominantly controls row-type variation in barley cultivars, and PRBS is a new locus related to the row type of spikes in barley.
