Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce th...Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce the 2n pollen formation by high temperature treatment.This study focused on the optimization of the 2n pollen induction technique and the mechanisms of high temperature-induced2n pollen formation in C.oleifera.We found that the optimal protocol for inducing 2n pollen via high temperature was to perform 45℃with4 h at the prophaseⅠstage of the pollen mother cells(PMCs).Meanwhile,high temperature significantly decreased the yield and fertility of2n pollen.Through the observation of meiosis,abnormal chromosome and cytological behaviour was discovered under high-temperature treatment,and we confirmed that the formation of 2n pollen is caused by abnormal cell plate.Based on weighted gene co-expression network analysis,fifteen hub genes related to cell cycle control were identified.After male flower buds were exposed to heat shock,polygalacturonase gene(CoPGX3)was significantly upregulated.We inferred that high temperature causes the CoPGX3 gene to be overexpressed and that CoPGX3 is redistributed into the cytosol where it degrades cytoplasmic pectin,which leads to an abnormal cell plate.Furthermore,abnormal cytokinesis resulted in the formation of dyads and triads,and PMCs divided to produce 2n pollen.Our findings provide new insights into the mechanism of 2n pollen induced by high temperature in a woody plant and lay a foundation for further ploidy breeding of C.oleifera.展开更多
Pollen analysis of 23 surface samples in the east of Qaidam Basin reveals the characteristics of pollen assemblages and their relationships with vegetation and climate. In pollen assemblages, Chenopodiaceae and Artemi...Pollen analysis of 23 surface samples in the east of Qaidam Basin reveals the characteristics of pollen assemblages and their relationships with vegetation and climate. In pollen assemblages, Chenopodiaceae and Artemisia are preponderant types in all the samples, and Ephedra, Gramineae and Compositae are common types. The results of DCA （Detrended Correspondance Analysis） and Correlation Analysis show different pollen assemblages indicate different vegetations, coincided with respective vegetation types. A/C （Artemisia/Chenopodiaceae） in the desert can indicate the aridity. Depending on the aridity, the vegetation communities are divided into four groups： severe drought group, moderate drought group, slight drought group and tropophilous group. A/C value is less 0.2 in the severe drought group, 0.2-0.5 in the moderate drought group, 1.63 in the slight drought group and 5.72 slight-wetness group.展开更多
[目的]研究不同处理方式对油茶（Camellia oleifera）花粉萌发率的影响。[方法]油茶品种为望漠油茶和岑溪软枝油茶。共设不同泡水时间和培养基处理。其中,泡水时间分别为0、10、20、30 m in,培养基分别为5%蔗糖＋100 mg/L硼酸＋3%琼脂、...[目的]研究不同处理方式对油茶（Camellia oleifera）花粉萌发率的影响。[方法]油茶品种为望漠油茶和岑溪软枝油茶。共设不同泡水时间和培养基处理。其中,泡水时间分别为0、10、20、30 m in,培养基分别为5%蔗糖＋100 mg/L硼酸＋3%琼脂、10%蔗糖＋100mg/L硼酸＋3%琼脂和20%蔗糖＋100 mg/L硼酸＋3%琼脂。[结果]在不泡水的情况下,望漠油茶花粉萌发最佳培养基是5%蔗糖＋100 mg/L硼酸＋3%琼脂,其花粉的萌发率为80.4%;岑溪软枝油茶花粉萌发的最佳培养基是10%蔗糖＋100 mg/L硼酸＋3%琼脂,其花粉的萌发率为88.5%。在采用相同培养基时,对油茶花粉泡水10~30 m in,花粉的平均萌发率仅为6.3%,最高萌发率为17.9%。[结论]该研究说明泡水对油茶花粉的生命力有极大损害。因此,在油茶人工辅助授粉中不宜采用水粉喷雾法。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.32101489)Forestry Science and Technology Innovation Program of Hunan Province(Grant No.XLK202101-2)Science and Technology Innovation Platform and Talent Program of Hunan Province(Grant Nos.2023RC3164,2021NK1007)。
文摘Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce the 2n pollen formation by high temperature treatment.This study focused on the optimization of the 2n pollen induction technique and the mechanisms of high temperature-induced2n pollen formation in C.oleifera.We found that the optimal protocol for inducing 2n pollen via high temperature was to perform 45℃with4 h at the prophaseⅠstage of the pollen mother cells(PMCs).Meanwhile,high temperature significantly decreased the yield and fertility of2n pollen.Through the observation of meiosis,abnormal chromosome and cytological behaviour was discovered under high-temperature treatment,and we confirmed that the formation of 2n pollen is caused by abnormal cell plate.Based on weighted gene co-expression network analysis,fifteen hub genes related to cell cycle control were identified.After male flower buds were exposed to heat shock,polygalacturonase gene(CoPGX3)was significantly upregulated.We inferred that high temperature causes the CoPGX3 gene to be overexpressed and that CoPGX3 is redistributed into the cytosol where it degrades cytoplasmic pectin,which leads to an abnormal cell plate.Furthermore,abnormal cytokinesis resulted in the formation of dyads and triads,and PMCs divided to produce 2n pollen.Our findings provide new insights into the mechanism of 2n pollen induced by high temperature in a woody plant and lay a foundation for further ploidy breeding of C.oleifera.
基金Scientific research fund of Hebei Normal University, No.L2004B14 National Key Basic Research Program, No.2005CB422005+3 种基金 National Natural Science Foundation of China, No.90202012 No.40171095 Natural Science Foundation of Hebei Province, No.402615 Knowledge Innovation Project of CAS, No.KZCX3-SW-339
文摘Pollen analysis of 23 surface samples in the east of Qaidam Basin reveals the characteristics of pollen assemblages and their relationships with vegetation and climate. In pollen assemblages, Chenopodiaceae and Artemisia are preponderant types in all the samples, and Ephedra, Gramineae and Compositae are common types. The results of DCA （Detrended Correspondance Analysis） and Correlation Analysis show different pollen assemblages indicate different vegetations, coincided with respective vegetation types. A/C （Artemisia/Chenopodiaceae） in the desert can indicate the aridity. Depending on the aridity, the vegetation communities are divided into four groups： severe drought group, moderate drought group, slight drought group and tropophilous group. A/C value is less 0.2 in the severe drought group, 0.2-0.5 in the moderate drought group, 1.63 in the slight drought group and 5.72 slight-wetness group.
文摘[目的]研究不同处理方式对油茶（Camellia oleifera）花粉萌发率的影响。[方法]油茶品种为望漠油茶和岑溪软枝油茶。共设不同泡水时间和培养基处理。其中,泡水时间分别为0、10、20、30 m in,培养基分别为5%蔗糖＋100 mg/L硼酸＋3%琼脂、10%蔗糖＋100mg/L硼酸＋3%琼脂和20%蔗糖＋100 mg/L硼酸＋3%琼脂。[结果]在不泡水的情况下,望漠油茶花粉萌发最佳培养基是5%蔗糖＋100 mg/L硼酸＋3%琼脂,其花粉的萌发率为80.4%;岑溪软枝油茶花粉萌发的最佳培养基是10%蔗糖＋100 mg/L硼酸＋3%琼脂,其花粉的萌发率为88.5%。在采用相同培养基时,对油茶花粉泡水10~30 m in,花粉的平均萌发率仅为6.3%,最高萌发率为17.9%。[结论]该研究说明泡水对油茶花粉的生命力有极大损害。因此,在油茶人工辅助授粉中不宜采用水粉喷雾法。
