The responses of dormancy induction to illumination and the characteristics of respiratory rate were studied with the nectarine peach bud in this article. The trial was conducted with nectarine （Prunus persica var. n...The responses of dormancy induction to illumination and the characteristics of respiratory rate were studied with the nectarine peach bud in this article. The trial was conducted with nectarine （Prunus persica var. nectariana cv. Shuguang） and involved three treatments： a short day treatment （8 h）, a long day treatment （16 h）, and the normal condition as the control. The dormancy status was determined with the growth of shoot and the sprouting ability, and the respiratory rate was mensurated with oxygen electrode. Short day treatment could induce the growth stopping of peach shoots ahead, promote the development of dormancy, and induce buds into dormancy with 21 d previous to control. Long day treatment postponed the growth stopping and the induction and development of dormancy. The respiratory rate decreased according to the development of dormancy induction. The minimum respiratory rate appeared about 7 days after the start of dormancy induction. Bud respiratory rate increased during this period and then declined and remained at low level during dormancy period. Long day reduced buds respiratory rate slightly. Short day could induce dormancy obviously, and long day postponed dormancy induction. The changes of respiratory rate were correlated with the development of dormancy induction, and the bud respiratory rate was also affected by photoperiod.展开更多
The yellow peach moth, Conogethes punctiferalis （Guenee）, a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperatur...The yellow peach moth, Conogethes punctiferalis （Guenee）, a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperature on larval diapause was examined under empirical laboratory conditions. Short-day treatments caused larval diapause at 25℃, and the critical photoperiod was between 12 and 13 h （or 12 h 51 min） light per day. No sensitive instar was identified for diapause induction under alternated short- （L ： D 11 ： 13 h） and long-day （L ： D 14 ： 10 h） treatments at different larval stages. However, accumulative treatment of three instars and 10 d under short-day treatment was required for the induction of 50% larval diapause. All larvae entered diapause at 20℃, whereas less than 3% did so at 30℃, irrespective of the long- or short-day treatment. Furthermore, under the short-day treatment, more than 90% of larvae went into diapause with temperatures ≤ 25℃, but less than 17% did so at 28℃. In contrast, under the long-day treatment, less than 19% of larvae went into diapause with temperatures ≥23 ℃. The forward shift （5℃） of critical temperature under the long-day regime demonstrated the compensatory effect of temperature and photoperiod on diapause induction. In conclusion, C. punctiferalis had a temperature-dependent type Ⅰ photoperiodic diapause response; there was no sensitive instar for diapause determination, but the photoperiodic accumulation time countermeasures both of the short-day cycles and the number ofinstars exposed, and the photoperiodic diapause response, was a temperature-compensated phenomenon.展开更多
The cabbage beetle, Colaphellus bowringiBaly （Coleoptera： Chrysomelidae）, is a serious pest of crucifers in China, undergoing an imaginal summer and winter diapause in the soil. The effects of host plants on diapau...The cabbage beetle, Colaphellus bowringiBaly （Coleoptera： Chrysomelidae）, is a serious pest of crucifers in China, undergoing an imaginal summer and winter diapause in the soil. The effects of host plants on diapause incidence were tested in the beetle. The ratio of adults entering diapause was significantly low when they fed on the mature leaves of Chinese cabbage Shanghaiqin （Brassica chinesis var communis） than those feeding on Chinese cabbage Suzhouqin （Brassica chinesis var communis）, radish （Raphanus sativus var longipinnatus） and stem mustard （Brassicajuncea vat tumida） at 25℃ combined with 13：11 （L： D） h. Fewer adults entered diapause on young leaves compared to physiologically aged and mature radish leaves at 25℃ combined with 13：11 （L： D） h. The effect of host plant species on diapause induction was also evident under continuously dark rearing conditions or at different photoperiods. These experimental results demonstrate that host plant mediation of diapause induction exists in the cabbage beetle. However, at temperatures ≤20℃ or photoperiods of 16：8 （L： D） h combined with 25℃, all individuals entered diapause regardless of the host plants, indicating that the effects of host plants on diapause induction could be expressed only within a limited range of temperatures and photoperiods.展开更多
Shuguang （Prunus persica var. nectariana cv. Shuguang） nectarine was used to study effects of photoperiod on key-enzyme activities of respiration during dormancy induction. The dormancy status was determined with sp...Shuguang （Prunus persica var. nectariana cv. Shuguang） nectarine was used to study effects of photoperiod on key-enzyme activities of respiration during dormancy induction. The dormancy status was determined with sprouting ability. Spectrophotometry was used to investigate activities of phosphohexose isomerase （PGI）, malic dehydrogenase （MDH）, and glucose-6-phosphate dehydrogenase （G6PDH）. The results revealed that short day （SD） treatment promoted dormancy induction while long day （LD） treatment postponed the process. During dormancy induction, PGI activities declined, MDH activities changed little, and G6PDH activities increased both in flower buds and leaf buds. PGI activities and MDH activities in SD treatment were lower than control, and G6PDH activities were higher, which was opposite with LD treatment. The changes of respiratory key-enzyme activities were adjusted by photoperiod and correlated with the development of dormancy induction.展开更多
Characteristics of dormancy induction and alternative respiration pathway （also known as cyanide-resistant respiration） of nectarine flower buds in different photoperiods were studied to determine the function of ph...Characteristics of dormancy induction and alternative respiration pathway （also known as cyanide-resistant respiration） of nectarine flower buds in different photoperiods were studied to determine the function of photoperiod and alternative respiration pathway in dormancy induction. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of alternative respiration pathway. The results showed that total respiration rate （Vt） in flower buds showed to be double hump-shaped curves. Short day raised, brought the first-hump of Vt forward and delayed the second-hump, while long day delayed the whole curve. The capacity （Vast） and activity （pValt） of SD and LD changed synchronously and both showed to be double hump-shaped curves. Short day made the first climax of Vast and pValt existed much earlier, while long day increased their rates significantly. The length of day had little effects on the later period climax. Long day also increased the contributions of altemative respiration pathway in total respiration rate （pValt/Vt）. The changes in alternative respiration pathway were correlated with the induction of dormancy and adjusted by photoperiod. Short day promoted dormancy induction of nectarine trees, while long day delayed it.展开更多
Flowering is essential in any breeding programme, particularly in genetic introgression programmes in which flowering synchronism is required. In this work, 16 sugarcane genotypes were evaluated using three different ...Flowering is essential in any breeding programme, particularly in genetic introgression programmes in which flowering synchronism is required. In this work, 16 sugarcane genotypes were evaluated using three different flowering-inductive photoperiod treatments (30 s, 45 s, and 1 min of a daily photoperiod decrease from 12 h 55 of light). Each genotype was planted in 43 L pots (equal proportion of soil, sand, and substrate) with three tillers per pot. Plants with 4 to 6 internodes were placed in a photoperiod facility with three controlled chambers, each chamber containing all 16 genotypes (one treatment per chamber). The temperature range (21°C to 32°C) and humidity were the same for all of the treatments. The flower induction started in September 2010 and ended in April 2011. The plant elongation and flag leaf and inflorescence emergence were recorded and the pollen viability was evaluated by using the iodine staining method. The photoperiod facility provided suitable conditions for flowering, as the plants in the three treatments successfully flowered. The genotypes in the three treatments behaved differently in relation to the date of panicle emergence, with the treatment of 45 s showing better results. The results here presented contribute to synchronise flowering for desired sugarcane crosses, particularly those from introgression programmes between commercial cultivars and species from the Saccharum complex.展开更多
The pine caterpillar Dendrolimus punctatus （Walker） with a larval facultative diapause is one of the most destructive insect pests of the pine tree Pinus massoniana in China. The larvae feeding on pine trees with di...The pine caterpillar Dendrolimus punctatus （Walker） with a larval facultative diapause is one of the most destructive insect pests of the pine tree Pinus massoniana in China. The larvae feeding on pine trees with different damage levels were studied to determine the induction of diapause under both laboratory and field conditions. Developmental duration of larvae before the third instar was the longest when fed with 75%-90% damaged needles, followed by 25%-40% damaged needles and intact pine needles, whereas mortalities did not differ among different treatments under the conditions of 25℃ and critical photoperiod 13.5：10.5 L：D. At 25 ℃, no diapause was induced under 15：9 L：D, whereas 100% diapause occurred under 12：12 L：D regardless of the levels of needle damage. Incidences of larvae entering diapause when they were fed with intact, 25%-40% and 75%- 90% damaged pine needles were 51.7%, 70.8% and 81% under 13.5：10.5 L：D, respectively. Similar results were obtained in the field experiment. Incidence of diapause was significantly different among the pine needle damage levels of pine trees when the photoperiod was close to the critical day length, indicating that the effect of host plants on diapause induction was dependent on the range of photoperiod. The content of amino acid and sugar decreased and tannin increased in pine needles after feeding by the pine caterpillars, suggesting that changed levels of nutrients in damaged needles or a particular substance emitted by damaged pine trees was perhaps involved in the diapause induction of the pine caterpillar.展开更多
基金the National 863 Program of China (2001AA247041)
文摘The responses of dormancy induction to illumination and the characteristics of respiratory rate were studied with the nectarine peach bud in this article. The trial was conducted with nectarine （Prunus persica var. nectariana cv. Shuguang） and involved three treatments： a short day treatment （8 h）, a long day treatment （16 h）, and the normal condition as the control. The dormancy status was determined with the growth of shoot and the sprouting ability, and the respiratory rate was mensurated with oxygen electrode. Short day treatment could induce the growth stopping of peach shoots ahead, promote the development of dormancy, and induce buds into dormancy with 21 d previous to control. Long day treatment postponed the growth stopping and the induction and development of dormancy. The respiratory rate decreased according to the development of dormancy induction. The minimum respiratory rate appeared about 7 days after the start of dormancy induction. Bud respiratory rate increased during this period and then declined and remained at low level during dormancy period. Long day reduced buds respiratory rate slightly. Short day could induce dormancy obviously, and long day postponed dormancy induction. The changes of respiratory rate were correlated with the development of dormancy induction, and the bud respiratory rate was also affected by photoperiod.
文摘The yellow peach moth, Conogethes punctiferalis （Guenee）, a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperature on larval diapause was examined under empirical laboratory conditions. Short-day treatments caused larval diapause at 25℃, and the critical photoperiod was between 12 and 13 h （or 12 h 51 min） light per day. No sensitive instar was identified for diapause induction under alternated short- （L ： D 11 ： 13 h） and long-day （L ： D 14 ： 10 h） treatments at different larval stages. However, accumulative treatment of three instars and 10 d under short-day treatment was required for the induction of 50% larval diapause. All larvae entered diapause at 20℃, whereas less than 3% did so at 30℃, irrespective of the long- or short-day treatment. Furthermore, under the short-day treatment, more than 90% of larvae went into diapause with temperatures ≤ 25℃, but less than 17% did so at 28℃. In contrast, under the long-day treatment, less than 19% of larvae went into diapause with temperatures ≥23 ℃. The forward shift （5℃） of critical temperature under the long-day regime demonstrated the compensatory effect of temperature and photoperiod on diapause induction. In conclusion, C. punctiferalis had a temperature-dependent type Ⅰ photoperiodic diapause response; there was no sensitive instar for diapause determination, but the photoperiodic accumulation time countermeasures both of the short-day cycles and the number ofinstars exposed, and the photoperiodic diapause response, was a temperature-compensated phenomenon.
文摘The cabbage beetle, Colaphellus bowringiBaly （Coleoptera： Chrysomelidae）, is a serious pest of crucifers in China, undergoing an imaginal summer and winter diapause in the soil. The effects of host plants on diapause incidence were tested in the beetle. The ratio of adults entering diapause was significantly low when they fed on the mature leaves of Chinese cabbage Shanghaiqin （Brassica chinesis var communis） than those feeding on Chinese cabbage Suzhouqin （Brassica chinesis var communis）, radish （Raphanus sativus var longipinnatus） and stem mustard （Brassicajuncea vat tumida） at 25℃ combined with 13：11 （L： D） h. Fewer adults entered diapause on young leaves compared to physiologically aged and mature radish leaves at 25℃ combined with 13：11 （L： D） h. The effect of host plant species on diapause induction was also evident under continuously dark rearing conditions or at different photoperiods. These experimental results demonstrate that host plant mediation of diapause induction exists in the cabbage beetle. However, at temperatures ≤20℃ or photoperiods of 16：8 （L： D） h combined with 25℃, all individuals entered diapause regardless of the host plants, indicating that the effects of host plants on diapause induction could be expressed only within a limited range of temperatures and photoperiods.
基金supported by the National High-Tech R&D Program (863) of China (2005AA247041)the Key Projects in the National Science & Technology Pillar Program of China during the 11th Five-Year Plan period (2006BAD07B06)
文摘Shuguang （Prunus persica var. nectariana cv. Shuguang） nectarine was used to study effects of photoperiod on key-enzyme activities of respiration during dormancy induction. The dormancy status was determined with sprouting ability. Spectrophotometry was used to investigate activities of phosphohexose isomerase （PGI）, malic dehydrogenase （MDH）, and glucose-6-phosphate dehydrogenase （G6PDH）. The results revealed that short day （SD） treatment promoted dormancy induction while long day （LD） treatment postponed the process. During dormancy induction, PGI activities declined, MDH activities changed little, and G6PDH activities increased both in flower buds and leaf buds. PGI activities and MDH activities in SD treatment were lower than control, and G6PDH activities were higher, which was opposite with LD treatment. The changes of respiratory key-enzyme activities were adjusted by photoperiod and correlated with the development of dormancy induction.
基金supported by the Key Projects in the National Science & Technology Pillar Program of China during the 11th Five-Year Plan period (2006BAD07B06)the Sci-Tech Innovation Fund for Young Scientists of Shandong Agricultural University,China (23658)
文摘Characteristics of dormancy induction and alternative respiration pathway （also known as cyanide-resistant respiration） of nectarine flower buds in different photoperiods were studied to determine the function of photoperiod and alternative respiration pathway in dormancy induction. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of alternative respiration pathway. The results showed that total respiration rate （Vt） in flower buds showed to be double hump-shaped curves. Short day raised, brought the first-hump of Vt forward and delayed the second-hump, while long day delayed the whole curve. The capacity （Vast） and activity （pValt） of SD and LD changed synchronously and both showed to be double hump-shaped curves. Short day made the first climax of Vast and pValt existed much earlier, while long day increased their rates significantly. The length of day had little effects on the later period climax. Long day also increased the contributions of altemative respiration pathway in total respiration rate （pValt/Vt）. The changes in alternative respiration pathway were correlated with the induction of dormancy and adjusted by photoperiod. Short day promoted dormancy induction of nectarine trees, while long day delayed it.
文摘Flowering is essential in any breeding programme, particularly in genetic introgression programmes in which flowering synchronism is required. In this work, 16 sugarcane genotypes were evaluated using three different flowering-inductive photoperiod treatments (30 s, 45 s, and 1 min of a daily photoperiod decrease from 12 h 55 of light). Each genotype was planted in 43 L pots (equal proportion of soil, sand, and substrate) with three tillers per pot. Plants with 4 to 6 internodes were placed in a photoperiod facility with three controlled chambers, each chamber containing all 16 genotypes (one treatment per chamber). The temperature range (21°C to 32°C) and humidity were the same for all of the treatments. The flower induction started in September 2010 and ended in April 2011. The plant elongation and flag leaf and inflorescence emergence were recorded and the pollen viability was evaluated by using the iodine staining method. The photoperiod facility provided suitable conditions for flowering, as the plants in the three treatments successfully flowered. The genotypes in the three treatments behaved differently in relation to the date of panicle emergence, with the treatment of 45 s showing better results. The results here presented contribute to synchronise flowering for desired sugarcane crosses, particularly those from introgression programmes between commercial cultivars and species from the Saccharum complex.
基金Acknowledgments We thank Drs. Roland Mumm, Yutong Qiu and Ties Huigens for their critical reading and helpful comments on an earlier version of the manuscript. This research was supported in part by Key Program of National Natural Science Foundation of China （30330490） and Project from Natural Science Foundation of Fujian Province （2007J0305）.
文摘The pine caterpillar Dendrolimus punctatus （Walker） with a larval facultative diapause is one of the most destructive insect pests of the pine tree Pinus massoniana in China. The larvae feeding on pine trees with different damage levels were studied to determine the induction of diapause under both laboratory and field conditions. Developmental duration of larvae before the third instar was the longest when fed with 75%-90% damaged needles, followed by 25%-40% damaged needles and intact pine needles, whereas mortalities did not differ among different treatments under the conditions of 25℃ and critical photoperiod 13.5：10.5 L：D. At 25 ℃, no diapause was induced under 15：9 L：D, whereas 100% diapause occurred under 12：12 L：D regardless of the levels of needle damage. Incidences of larvae entering diapause when they were fed with intact, 25%-40% and 75%- 90% damaged pine needles were 51.7%, 70.8% and 81% under 13.5：10.5 L：D, respectively. Similar results were obtained in the field experiment. Incidence of diapause was significantly different among the pine needle damage levels of pine trees when the photoperiod was close to the critical day length, indicating that the effect of host plants on diapause induction was dependent on the range of photoperiod. The content of amino acid and sugar decreased and tannin increased in pine needles after feeding by the pine caterpillars, suggesting that changed levels of nutrients in damaged needles or a particular substance emitted by damaged pine trees was perhaps involved in the diapause induction of the pine caterpillar.
