In order to study the effect of rice straw returning and seeding patterns on seedling emergence and grain yield, field experiment was conducted to investi- gate the effects of straw mechanized returning and different ...In order to study the effect of rice straw returning and seeding patterns on seedling emergence and grain yield, field experiment was conducted to investi- gate the effects of straw mechanized returning and different seeding patterns on e- mergence rate, emergence uniformity and yield traits of wheat after rice. The results were as follows： in rice straw removal treatments, the emergence rate of mechani- cal seeding in drill was lower than that of mechanical uniform planting and manual broadcast sowing, which were 51.84%, 90.89% and 88.87%, respectively; the emer- gence uniformity of manual broadcast sowing was inferior to mechanical seeding in drill and mechanical uniform planting, which were 0.49, 0.26 and 0.23, respectively. As for the treatments with rice straw returning to the field, the emergence rate and emergence uniformity all decreased in the three seeding patterns, of which mechan- ical seeding in drill dropped markedly with emergence rate decreased by 36.54%. The emergence rate and emergence uniformity affected grain yield by affecting pan- icle, grains per spike and 1 000-grain weight. The grain yield for the treatment with rice straw removal was 6 091.34 kg/hm2, while that with rice straw returning to field was 6 476.20 kg/hm2, and both were higher than the yields of the other two seed- ing patterns. Therefore, mechanical uniform planting was？recommended for its higher emergence rate, better emergence uniformity, which was conductive to increase grain yield in wheat after rice production with rice straw returning to field.展开更多
To provide an insight into the molecular basis of heterosis, differential display of mRNA was used to analyze the difference of gene expression between wheat (Triticum aestivum L.) heterotic hybrid A, nonheterotic hyb...To provide an insight into the molecular basis of heterosis, differential display of mRNA was used to analyze the difference of gene expression between wheat (Triticum aestivum L.) heterotic hybrid A, nonheterotic hybrid B and their parental inbreds in the primary roots. By using 5′ end random primers in combination with three one-base-anchored primers, it was found that 22.5% and 22.9% of 877 total displayed cDNAs were differentially expressed between hybrid A, B and their parents, respectively. Both quantitative and qualitative differences in gene expression between hybrids and their parental inbreds were obvious, indicating that the patterns of gene expression in hybrids alter significantly as compared to their corresponding parents. On the other hand, by using MADS-box gene specific 5′ end primer for DDRT-PCR, we found that nearly all of the displayed cDNA fragments were polymorphic between hybrids and their parents, and major difference occurred in qualitative level, in which hybrid specific-expressed and silenced genes are the major two patterns, suggesting that MADS-box gene may be important for manifestation of differential gene expression and wheat heterosis. In comparison with our previous results by using seedling leaves, it is indicated that differential gene expression between hybrids and parents is dependent on the tissues tested, and more differentially expressed genes were observed in the primary roots than in the seedling leaves. Therefore, it is concluded that the expressions of both randomly displayed cDNAs and transcription factor genes, such as MADS-box, alter significantly between hybrids and their parents, which might be responsible for the observed heterosis.展开更多
Toxicity of the different concentration of Cu^2＋ to the wheat seeding and its distribution in the plant were studied by solution culture. The results showed that： The correlation between the content of Cu^2＋ in med...Toxicity of the different concentration of Cu^2＋ to the wheat seeding and its distribution in the plant were studied by solution culture. The results showed that： The correlation between the content of Cu^2＋ in medium and the germination and growth of the seedlings is significant （P〈0.01）. The effect of Cu^2＋ to the germination, plant height, fresh weight, dried weight and the chlorophyll mount of the wheat seedling was stimulated under lower concentration of Cu^2＋ and was inhibited under higher concentration. With the increase of the Cu^2＋ concentration in the culture solution, the germination and growth of the seedlings was inhibited. The perfect positive correlation between the Cu^2＋ content in the plant and that in the culture solution was noted. Most of Cu^2＋ was concentrated in the root, and only a small amount was migrated to the aerial part of the wheat seedling. The sensitivity of each index to the Cu^2＋ concentration was ranked as follows： the Cu^2＋ content in the plant〉chlorophyll-a〉the ratio of chlorophyll-a to chlorophyll-b〉total chlorophyll〉plant height 〉germination〉fresh weight〉root elongation〉 chlorophyll-b 〉dried weight. The Cu^2＋ content in the wheat plant was the most sensitive index to the Cu^2＋ concentration in the culture solution.展开更多
文摘In order to study the effect of rice straw returning and seeding patterns on seedling emergence and grain yield, field experiment was conducted to investi- gate the effects of straw mechanized returning and different seeding patterns on e- mergence rate, emergence uniformity and yield traits of wheat after rice. The results were as follows： in rice straw removal treatments, the emergence rate of mechani- cal seeding in drill was lower than that of mechanical uniform planting and manual broadcast sowing, which were 51.84%, 90.89% and 88.87%, respectively; the emer- gence uniformity of manual broadcast sowing was inferior to mechanical seeding in drill and mechanical uniform planting, which were 0.49, 0.26 and 0.23, respectively. As for the treatments with rice straw returning to the field, the emergence rate and emergence uniformity all decreased in the three seeding patterns, of which mechan- ical seeding in drill dropped markedly with emergence rate decreased by 36.54%. The emergence rate and emergence uniformity affected grain yield by affecting pan- icle, grains per spike and 1 000-grain weight. The grain yield for the treatment with rice straw removal was 6 091.34 kg/hm2, while that with rice straw returning to field was 6 476.20 kg/hm2, and both were higher than the yields of the other two seed- ing patterns. Therefore, mechanical uniform planting was？recommended for its higher emergence rate, better emergence uniformity, which was conductive to increase grain yield in wheat after rice production with rice straw returning to field.
文摘To provide an insight into the molecular basis of heterosis, differential display of mRNA was used to analyze the difference of gene expression between wheat (Triticum aestivum L.) heterotic hybrid A, nonheterotic hybrid B and their parental inbreds in the primary roots. By using 5′ end random primers in combination with three one-base-anchored primers, it was found that 22.5% and 22.9% of 877 total displayed cDNAs were differentially expressed between hybrid A, B and their parents, respectively. Both quantitative and qualitative differences in gene expression between hybrids and their parental inbreds were obvious, indicating that the patterns of gene expression in hybrids alter significantly as compared to their corresponding parents. On the other hand, by using MADS-box gene specific 5′ end primer for DDRT-PCR, we found that nearly all of the displayed cDNA fragments were polymorphic between hybrids and their parents, and major difference occurred in qualitative level, in which hybrid specific-expressed and silenced genes are the major two patterns, suggesting that MADS-box gene may be important for manifestation of differential gene expression and wheat heterosis. In comparison with our previous results by using seedling leaves, it is indicated that differential gene expression between hybrids and parents is dependent on the tissues tested, and more differentially expressed genes were observed in the primary roots than in the seedling leaves. Therefore, it is concluded that the expressions of both randomly displayed cDNAs and transcription factor genes, such as MADS-box, alter significantly between hybrids and their parents, which might be responsible for the observed heterosis.
文摘Toxicity of the different concentration of Cu^2＋ to the wheat seeding and its distribution in the plant were studied by solution culture. The results showed that： The correlation between the content of Cu^2＋ in medium and the germination and growth of the seedlings is significant （P〈0.01）. The effect of Cu^2＋ to the germination, plant height, fresh weight, dried weight and the chlorophyll mount of the wheat seedling was stimulated under lower concentration of Cu^2＋ and was inhibited under higher concentration. With the increase of the Cu^2＋ concentration in the culture solution, the germination and growth of the seedlings was inhibited. The perfect positive correlation between the Cu^2＋ content in the plant and that in the culture solution was noted. Most of Cu^2＋ was concentrated in the root, and only a small amount was migrated to the aerial part of the wheat seedling. The sensitivity of each index to the Cu^2＋ concentration was ranked as follows： the Cu^2＋ content in the plant〉chlorophyll-a〉the ratio of chlorophyll-a to chlorophyll-b〉total chlorophyll〉plant height 〉germination〉fresh weight〉root elongation〉 chlorophyll-b 〉dried weight. The Cu^2＋ content in the wheat plant was the most sensitive index to the Cu^2＋ concentration in the culture solution.
