The levels of endogenous plant hormones regulate floret development and degeneration, and thus grain set in flower crops. This study was undertaken to characterize the changes of endogenous hormone levels during flor...The levels of endogenous plant hormones regulate floret development and degeneration, and thus grain set in flower crops. This study was undertaken to characterize the changes of endogenous hormone levels during floret development in three wheat ( Triticum aestivum L.) genotypes: “97J1' with the highest grain set and fertile florets per spike, “H8679' with the lowest grain set and fertile florets per spike, and a medium, “YM158'. The results showed that the peak level of ABA appeared between stamen and pistil differentiation and antherlobe formation of floret development, and the timing delayed with the size of spike (earliest in “H8679” and latest in “97J1”). From antherlobe formation to meiosis, the levels of ABA and GA 1+3 decreased sharply in the ears of “97J1”, while in the ears of “H8679” there was only a slight decrease in ABA, and even an increase in GA 1+3 . The ratio of isopentenyladenosine (iPA)/ABA and IAA/ABA in the ears of “97J1” increased sharply from antherlobe formation to meiosis, but changed only slightly in the ears of “H8679”. At antherlobe formation, IAA and GA 1+3 levels were higher in the ears of “97J1”, but lower in the ears of “H8679” than in the leaves. At meiosis, ABA, GA 1+3 and IAA levels in the “97J1” ears were much lower than in the leaves, but similar in “H8679”. These results indicated that the sharp decreases of ABA and GA 1+3 in ears from antherlobe formation to meiosis and the lowest maintenance at meiosis may be favorable for development of fertile florets and enhancement of grain set in wheat.展开更多
The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops ...The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops variabilis Eig. (or rye), a significant increase in the chiasmata of homoeologous pairing was shown by the phKL+Ph2(-) plants with respect to their phKL+Ph2 sibs, which indicates that Ph2-deficiency and phKL showed an additive effect on promoting pairing. The effects were shown in the increment of rod bivalents, ring bivalents and trivalents and reduction of univalents, of which, reduction of univalents was mainly due to the increment of rod bivalents. The combined lines are probably more desirable materials for alien gene transferring than phKL or Ph2(-) lines alone. In comparison with that of ph1b X Ae. variabilis (or rye), phKL+Ph2(-) X Ae. variabilis (or rye) show higher (or similar) numbers of rod bivalents, while the total chromosome pairing level significantly reduced that ascribed to the decrement in ring bivalents and multivalents. These results probably indicate the different genetic mechanisms for Ph1 and Ph2 or phKL on controlling homoeologous pairing.展开更多
Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resis...Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resistant homologous sequences in the near isogenic lines (NILs) of powdery mildew resistance using RT-PCR method. Two expressed cDNA fragments were isolated from wheat genome. One showed 83% homology to the Mlo gene of barley. The other contained two possible open reading frames (ORFs). NBS conservative domains 2, 3 of disease resistance gene and 13 LRR structures similar to rice Pib protein terminal were found respectively in the two ORFs. It indicated that the latter fragment belongs to NBS-LRR-like genes. The obvious difference of RT-PCR products was observed between the before challenged and the challenged for 72 h by Blumeria graminis f. sp. tritici, which, implied that this sequence could be associated with disease resistance of wheat. Using nulli-tetrasomic lines of 'Chinese Spring', the NBS-LRR-like gene had been located on chromosome 1D.展开更多
In the study, the methods of applied histology and histochemistry were used to determine intestinal villus length, crypt depth, the ratio of intestinal villus length to crypt depth, mucous membrane thickness and intes...In the study, the methods of applied histology and histochemistry were used to determine intestinal villus length, crypt depth, the ratio of intestinal villus length to crypt depth, mucous membrane thickness and intestinal wall thickness of duodenum, jejunum and ileum of 42-day-old broilers, so as to study the effects of different conncentrations of homologous probiottcs on small intestinal mucosa struc- ture of the broilers. The results showed that the effect of 0.3% probiotics on small intestine mucosal structures was the best, such as the length of intestinal villus was the longest, the ratio of villus length to crypt depth was the largest, the thins of mucous membrane and intestinal wall was the thickest. These showed that 0,3% probiotics had best effect on improving and enhancing the digestion-absorption func- tion of the small intestine of the broilers.展开更多
[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the secon...[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the second last leaf （L2）,removing upper part of spike （L3） and controlling （CK） were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat＇s 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat＇s 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat.展开更多
Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD...Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed.展开更多
The effects of exogenous growth regulating substance on the fruit weight of peach were reviewed. Paclobutrazol could increase the single fruit weight in dif- ferent degree, and cytokinins could also increase the singl...The effects of exogenous growth regulating substance on the fruit weight of peach were reviewed. Paclobutrazol could increase the single fruit weight in dif- ferent degree, and cytokinins could also increase the single fruit weight. GA3 and B9 had no effect on fruit size or on reducing single fruit weight. Chlorflurenol-methy, ABT and salicylic acid had no effect on fruit size. Suggestions on the future re- search were put forward.展开更多
文摘The levels of endogenous plant hormones regulate floret development and degeneration, and thus grain set in flower crops. This study was undertaken to characterize the changes of endogenous hormone levels during floret development in three wheat ( Triticum aestivum L.) genotypes: “97J1' with the highest grain set and fertile florets per spike, “H8679' with the lowest grain set and fertile florets per spike, and a medium, “YM158'. The results showed that the peak level of ABA appeared between stamen and pistil differentiation and antherlobe formation of floret development, and the timing delayed with the size of spike (earliest in “H8679” and latest in “97J1”). From antherlobe formation to meiosis, the levels of ABA and GA 1+3 decreased sharply in the ears of “97J1”, while in the ears of “H8679” there was only a slight decrease in ABA, and even an increase in GA 1+3 . The ratio of isopentenyladenosine (iPA)/ABA and IAA/ABA in the ears of “97J1” increased sharply from antherlobe formation to meiosis, but changed only slightly in the ears of “H8679”. At antherlobe formation, IAA and GA 1+3 levels were higher in the ears of “97J1”, but lower in the ears of “H8679” than in the leaves. At meiosis, ABA, GA 1+3 and IAA levels in the “97J1” ears were much lower than in the leaves, but similar in “H8679”. These results indicated that the sharp decreases of ABA and GA 1+3 in ears from antherlobe formation to meiosis and the lowest maintenance at meiosis may be favorable for development of fertile florets and enhancement of grain set in wheat.
文摘The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops variabilis Eig. (or rye), a significant increase in the chiasmata of homoeologous pairing was shown by the phKL+Ph2(-) plants with respect to their phKL+Ph2 sibs, which indicates that Ph2-deficiency and phKL showed an additive effect on promoting pairing. The effects were shown in the increment of rod bivalents, ring bivalents and trivalents and reduction of univalents, of which, reduction of univalents was mainly due to the increment of rod bivalents. The combined lines are probably more desirable materials for alien gene transferring than phKL or Ph2(-) lines alone. In comparison with that of ph1b X Ae. variabilis (or rye), phKL+Ph2(-) X Ae. variabilis (or rye) show higher (or similar) numbers of rod bivalents, while the total chromosome pairing level significantly reduced that ascribed to the decrement in ring bivalents and multivalents. These results probably indicate the different genetic mechanisms for Ph1 and Ph2 or phKL on controlling homoeologous pairing.
文摘Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resistant homologous sequences in the near isogenic lines (NILs) of powdery mildew resistance using RT-PCR method. Two expressed cDNA fragments were isolated from wheat genome. One showed 83% homology to the Mlo gene of barley. The other contained two possible open reading frames (ORFs). NBS conservative domains 2, 3 of disease resistance gene and 13 LRR structures similar to rice Pib protein terminal were found respectively in the two ORFs. It indicated that the latter fragment belongs to NBS-LRR-like genes. The obvious difference of RT-PCR products was observed between the before challenged and the challenged for 72 h by Blumeria graminis f. sp. tritici, which, implied that this sequence could be associated with disease resistance of wheat. Using nulli-tetrasomic lines of 'Chinese Spring', the NBS-LRR-like gene had been located on chromosome 1D.
基金Supported by the Project of Beijing Vocational College of Agriculture(XY-YF-14-18XYYF-14-16)~~
文摘In the study, the methods of applied histology and histochemistry were used to determine intestinal villus length, crypt depth, the ratio of intestinal villus length to crypt depth, mucous membrane thickness and intestinal wall thickness of duodenum, jejunum and ileum of 42-day-old broilers, so as to study the effects of different conncentrations of homologous probiottcs on small intestinal mucosa struc- ture of the broilers. The results showed that the effect of 0.3% probiotics on small intestine mucosal structures was the best, such as the length of intestinal villus was the longest, the ratio of villus length to crypt depth was the largest, the thins of mucous membrane and intestinal wall was the thickest. These showed that 0,3% probiotics had best effect on improving and enhancing the digestion-absorption func- tion of the small intestine of the broilers.
基金Supported by Jiangsu High School Natural Science Fund(09KJB210004)Undergraduate Practice Innovation Project of Nanjing University of Information Science & Technology (09CX0025 )Educational Reform Project of Nanjing University of Information Science &Technology (09JY0036)~~
文摘[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the second last leaf （L2）,removing upper part of spike （L3） and controlling （CK） were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat＇s 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat＇s 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat.
文摘Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed.
基金Supported by the Planning Subject of"the Twelfth Five-year-plan"in National Science and Technology for the Rural Development in China(2013BAD02B03-1-03-1)the China Agricultural Research System for Peach Industry(CARS-31-Z-2)+1 种基金the Key Technology R&D Program of Hebei Province(14226301D)the Special Financial Program of Hebei Province(494-0402-JBN-J42L)~~
文摘The effects of exogenous growth regulating substance on the fruit weight of peach were reviewed. Paclobutrazol could increase the single fruit weight in dif- ferent degree, and cytokinins could also increase the single fruit weight. GA3 and B9 had no effect on fruit size or on reducing single fruit weight. Chlorflurenol-methy, ABT and salicylic acid had no effect on fruit size. Suggestions on the future re- search were put forward.
