Four pairs of microsatellite molecular polymorphism primers were used to analyse microsatellite fingerprints of 188 seedlings derived from an open-pollinated progeny grafted Eucalyptus globulus breeding arboretum in V...Four pairs of microsatellite molecular polymorphism primers were used to analyse microsatellite fingerprints of 188 seedlings derived from an open-pollinated progeny grafted Eucalyptus globulus breeding arboretum in Victoria, south-eastern Australia. The microsatellite loci chosen for this study were highly polymorphic with the mean number of alleles per locus of 14.25. Individual mothers varied in their outcrosssing rate estimate from 15% to 95%, the overall outcrossing level in the arboretum was 47.9% and the contamination rate was 17.6%. The high selfing level was likely to result in marked inbreeding depression in the performance of open-pollinated seed lots. Open-pollinated seeds collected from such arboreta are not advisable because of its low genetic quality, although such arboreta may be useful for the seed production through large-scale manual pollination or collecting seeds only from trees or genotypes within the arboretum that have high outcrossing rates.展开更多
Pollen viability study on Piper colubrinum Link. carried out to develop interspecific hybridization between P. nigrum L. and P. colubrinum Link.. This plant has good potential as a donor plant in breeding programme fo...Pollen viability study on Piper colubrinum Link. carried out to develop interspecific hybridization between P. nigrum L. and P. colubrinum Link.. This plant has good potential as a donor plant in breeding programme for Phytophthora to foot rot resistance in the cultivated species, P. nigrum. This project was carried out to reveal the optimum time to collect pollen of P. colubrinum for artificial pollination. Through this study, anther dehiscence was proved occurred around 9 am. Based on the result obtained from study on the time of anther dehiscence, the pollen was classified into five stages for testing on the viability, i.e., stage 1, before anther dehiscence, i.e., around 7 am （pollen obtained by crushing on the anther）; stage 2： immediately after anther dehiscence, i.e., around 9 am; stage 3： two hours after anther dehiscence, i.e., around 11 am; stage 4： four hours after anther dehiscence, i.e., around 1 pm; and stage 5： six hours after anther dehiscence, i.e., around 3 pm. Data obtained from pollen germination and pollen tube growth study showed that pollen of P. colubrinum was the most viable at two hours after anther dehiscence and onward. It was also proved that the viability can be maintained up to at least eight hours. Pollen obtained before anther dehiscence by crushing on the anther was found less viable with lower percentage of pollen germination and retarded pollen tube growth. In other words, the experiment enlightened that artificial pollination between P. nigrum L. and P. colubrinum Link was ideally to be carded out approximately starting from 11 am until 5 pm, considering the viability of pollen ofP. colubrinum.展开更多
[Objective] The purpose was to study and analyze the difference of Peiai 64 S fertility expression in two different climatic regions, Hainan and Hunan in 2010, and confirm the suitable region for its production of hyb...[Objective] The purpose was to study and analyze the difference of Peiai 64 S fertility expression in two different climatic regions, Hainan and Hunan in 2010, and confirm the suitable region for its production of hybrid seeds. [Method] Eight sowing times were designed, March 20 and 30, April 10 and 30, May 15, June 1, 10 and 20, respectively in Changsha of Hunan. Thirteen sowing times were designed in Hainan, January 28, February 12 and 27, March 14 and 29, April 13 and 28, May 13 and 28, June 12, July 1, 12 and 27, respectively. Peiai 64S was gradually managed and recorded heading stage during cultivation, and the effects of different climate influencing factors, such as daily mean temperature, daily maximum temperature, daily minimum temperature, duration of day at 0-25 d before heading （namely pollen mother cell meiophase）, on pollen fertility were analyzed to confirm sensitive periods of light and temperature. [ResuLt] There was a big difference in sensitive period among the same cytoplasmic male sterile （CMS） in different climatic regions. The sensitive period of Peiai 64S was in first four phases, phases V, VI, VII, VIII （0-13 d） in Changsha of Hunan, which was in last four phases, phases I, II, III, IV （13-25 d） in Haikou of Hainan. Under natural conditions, Peiai 64S pollen sterility rate were all more than 99.5% and seed-setting rates all less than 0.5% in Haikou, so production of hybrid seeds was safe. Its pollen sterility rate was 21.3%- 100.0% in Hunan, so its security coefficient of hybrid seeds production was lower than that in Hainan. [Conclusion] The security coefficient of hybrid seeds production of CMS Peiai 64S is lower than that in Hainan.展开更多
[Objective] This study aimed to explore methods for improving hybrid seed-setting rate of a potato cultivar Linshu 17. [Method] L0527-4 was taken as male parent and Linshu 17 was taken as female parent to breed a new ...[Objective] This study aimed to explore methods for improving hybrid seed-setting rate of a potato cultivar Linshu 17. [Method] L0527-4 was taken as male parent and Linshu 17 was taken as female parent to breed a new potato cul- tivar, so as to take advantage of the excellent characters of Linshu 17. [Result] The optimum pollination time of Linshu 17 was 10：00-12：00 am or after 04：00 pm. Spraying 10 mg/L of 2, 4-D, 50 mg/L of gibberellin or 20 mg/L of 6-BA ＋ 50 mg/L of gibberellin once every 7 days since the 3^rd day after hybridization all could im- prove the hybrid seed-setting rate of Linshu 17. [Conclusion] The hybrid seed-setting rate-improving effect of 2, 4-D sprayed on the 3^rd d after hybridization was best for Linshu 17. This study will provide technical references for other varieties to improve the hybrid seed-setting rate.展开更多
基金This study was supported by State Administration of Foreign Experts Affairs, P. R. China (No.2001430007)
文摘Four pairs of microsatellite molecular polymorphism primers were used to analyse microsatellite fingerprints of 188 seedlings derived from an open-pollinated progeny grafted Eucalyptus globulus breeding arboretum in Victoria, south-eastern Australia. The microsatellite loci chosen for this study were highly polymorphic with the mean number of alleles per locus of 14.25. Individual mothers varied in their outcrosssing rate estimate from 15% to 95%, the overall outcrossing level in the arboretum was 47.9% and the contamination rate was 17.6%. The high selfing level was likely to result in marked inbreeding depression in the performance of open-pollinated seed lots. Open-pollinated seeds collected from such arboreta are not advisable because of its low genetic quality, although such arboreta may be useful for the seed production through large-scale manual pollination or collecting seeds only from trees or genotypes within the arboretum that have high outcrossing rates.
文摘Pollen viability study on Piper colubrinum Link. carried out to develop interspecific hybridization between P. nigrum L. and P. colubrinum Link.. This plant has good potential as a donor plant in breeding programme for Phytophthora to foot rot resistance in the cultivated species, P. nigrum. This project was carried out to reveal the optimum time to collect pollen of P. colubrinum for artificial pollination. Through this study, anther dehiscence was proved occurred around 9 am. Based on the result obtained from study on the time of anther dehiscence, the pollen was classified into five stages for testing on the viability, i.e., stage 1, before anther dehiscence, i.e., around 7 am （pollen obtained by crushing on the anther）; stage 2： immediately after anther dehiscence, i.e., around 9 am; stage 3： two hours after anther dehiscence, i.e., around 11 am; stage 4： four hours after anther dehiscence, i.e., around 1 pm; and stage 5： six hours after anther dehiscence, i.e., around 3 pm. Data obtained from pollen germination and pollen tube growth study showed that pollen of P. colubrinum was the most viable at two hours after anther dehiscence and onward. It was also proved that the viability can be maintained up to at least eight hours. Pollen obtained before anther dehiscence by crushing on the anther was found less viable with lower percentage of pollen germination and retarded pollen tube growth. In other words, the experiment enlightened that artificial pollination between P. nigrum L. and P. colubrinum Link was ideally to be carded out approximately starting from 11 am until 5 pm, considering the viability of pollen ofP. colubrinum.
文摘[Objective] The purpose was to study and analyze the difference of Peiai 64 S fertility expression in two different climatic regions, Hainan and Hunan in 2010, and confirm the suitable region for its production of hybrid seeds. [Method] Eight sowing times were designed, March 20 and 30, April 10 and 30, May 15, June 1, 10 and 20, respectively in Changsha of Hunan. Thirteen sowing times were designed in Hainan, January 28, February 12 and 27, March 14 and 29, April 13 and 28, May 13 and 28, June 12, July 1, 12 and 27, respectively. Peiai 64S was gradually managed and recorded heading stage during cultivation, and the effects of different climate influencing factors, such as daily mean temperature, daily maximum temperature, daily minimum temperature, duration of day at 0-25 d before heading （namely pollen mother cell meiophase）, on pollen fertility were analyzed to confirm sensitive periods of light and temperature. [ResuLt] There was a big difference in sensitive period among the same cytoplasmic male sterile （CMS） in different climatic regions. The sensitive period of Peiai 64S was in first four phases, phases V, VI, VII, VIII （0-13 d） in Changsha of Hunan, which was in last four phases, phases I, II, III, IV （13-25 d） in Haikou of Hainan. Under natural conditions, Peiai 64S pollen sterility rate were all more than 99.5% and seed-setting rates all less than 0.5% in Haikou, so production of hybrid seeds was safe. Its pollen sterility rate was 21.3%- 100.0% in Hunan, so its security coefficient of hybrid seeds production was lower than that in Hainan. [Conclusion] The security coefficient of hybrid seeds production of CMS Peiai 64S is lower than that in Hainan.
文摘[Objective] This study aimed to explore methods for improving hybrid seed-setting rate of a potato cultivar Linshu 17. [Method] L0527-4 was taken as male parent and Linshu 17 was taken as female parent to breed a new potato cul- tivar, so as to take advantage of the excellent characters of Linshu 17. [Result] The optimum pollination time of Linshu 17 was 10：00-12：00 am or after 04：00 pm. Spraying 10 mg/L of 2, 4-D, 50 mg/L of gibberellin or 20 mg/L of 6-BA ＋ 50 mg/L of gibberellin once every 7 days since the 3^rd day after hybridization all could im- prove the hybrid seed-setting rate of Linshu 17. [Conclusion] The hybrid seed-setting rate-improving effect of 2, 4-D sprayed on the 3^rd d after hybridization was best for Linshu 17. This study will provide technical references for other varieties to improve the hybrid seed-setting rate.
