To learn about the phenological adaptation of <i><span style="font-family:Verdana;">Lactuca</span></i> <i><span style="font-family:Verdana;">georgica</span>...To learn about the phenological adaptation of <i><span style="font-family:Verdana;">Lactuca</span></i> <i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> Grossh., a wild relative of domesticated lettuce, we studied seed sampled accessions obtained from individual plants at 19 locations throughout six regions in Armenia, and from two natural populations in Dagestan (Russian Federation) collected as bulk samples. The effects of various vernalization treatments on time to bolting, flowering and seed production time were investigated during four successive years at different growth stages of </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> plants. We demonstrate that low temperatures play a major role in stimulating the reproduction process of </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> plants. Our results would suggest that for </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;">: 1) There is an obligatory (or nearly so) vernalization requirement;2) Plant age, vernalization duration, and genotype of original sample have a role in bolting and flowering regulation;3) Some plants behaved as typical annuals, responding to vernalization treatment at the seedling stage, but, most did not;4) Four months of vernalization could be adequate to reach bolting in plants with a developed vegetative rosette, for most—but not all—samples;5) In order to find the best solution for stimulating the reproductive process of multiple genotypes, it seems that further study should focus on about 4 - 6 months of vernalization at 4°C applied to plants of about 10 - 22 展开更多
Based on the analysis of previous genetic algorithms (GAs) for TSP, a novel method called Ge- GA is proposed. It combines gene pool and GA so as to direct the evolution of the whole population. The core of Ge- GA is t...Based on the analysis of previous genetic algorithms (GAs) for TSP, a novel method called Ge- GA is proposed. It combines gene pool and GA so as to direct the evolution of the whole population. The core of Ge- GA is the construction of gene pool and how to apply it to GA. Different from standard GAs, Ge- GA aims to enhance the ability of exploration and exploitation by incorporating global search with local search. On one hand a local search called Ge- Lo-calSearch operator is proposed to improve the solution quality, on the other hand the modified Inver-Over operator called Ge InverOver is considered as a global search mechanism to expand solution space of local minimal. Both of these operators are based on the gene pool. Our algorithm is applied to 11 well-known traveling salesman problems whose numbers of cities are from 70 to 1577 cities. The experiments results indicate that Ge- GA has great robustness for TSP. For each test instance, the average value of solution quality, found in accepted time, stays within 0. 001% from the optimum.展开更多
针对传统遗传算法(genetic algorithm,GA)求解旅行商问题(traveling salesman problem,TSP)存在寻优效率低、实验结果缺乏一致性等问题,提出了一种基于基因库的遗传算法(genetic algorithm based on genes pool,GPGA)。GPGA从种群中搜...针对传统遗传算法(genetic algorithm,GA)求解旅行商问题(traveling salesman problem,TSP)存在寻优效率低、实验结果缺乏一致性等问题,提出了一种基于基因库的遗传算法(genetic algorithm based on genes pool,GPGA)。GPGA从种群中搜索减小哈密顿圈长度的边,并当做优良基因构成基因库。父代哈密顿圈在基因库引导下产生更优的子代哈密顿圈,基因库也随着种群的不断进化而同步更新,引导种群个体逐步向最优解靠近。算例结果表明在同样条件下,GPGA比传统遗传算法和几种改进遗传算法的性能更优。展开更多
文摘To learn about the phenological adaptation of <i><span style="font-family:Verdana;">Lactuca</span></i> <i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> Grossh., a wild relative of domesticated lettuce, we studied seed sampled accessions obtained from individual plants at 19 locations throughout six regions in Armenia, and from two natural populations in Dagestan (Russian Federation) collected as bulk samples. The effects of various vernalization treatments on time to bolting, flowering and seed production time were investigated during four successive years at different growth stages of </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> plants. We demonstrate that low temperatures play a major role in stimulating the reproduction process of </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> plants. Our results would suggest that for </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;">: 1) There is an obligatory (or nearly so) vernalization requirement;2) Plant age, vernalization duration, and genotype of original sample have a role in bolting and flowering regulation;3) Some plants behaved as typical annuals, responding to vernalization treatment at the seedling stage, but, most did not;4) Four months of vernalization could be adequate to reach bolting in plants with a developed vegetative rosette, for most—but not all—samples;5) In order to find the best solution for stimulating the reproductive process of multiple genotypes, it seems that further study should focus on about 4 - 6 months of vernalization at 4°C applied to plants of about 10 - 22
基金Supported by the National Natural Science Foundation of China(70071042,60073043,and 60133010)
文摘Based on the analysis of previous genetic algorithms (GAs) for TSP, a novel method called Ge- GA is proposed. It combines gene pool and GA so as to direct the evolution of the whole population. The core of Ge- GA is the construction of gene pool and how to apply it to GA. Different from standard GAs, Ge- GA aims to enhance the ability of exploration and exploitation by incorporating global search with local search. On one hand a local search called Ge- Lo-calSearch operator is proposed to improve the solution quality, on the other hand the modified Inver-Over operator called Ge InverOver is considered as a global search mechanism to expand solution space of local minimal. Both of these operators are based on the gene pool. Our algorithm is applied to 11 well-known traveling salesman problems whose numbers of cities are from 70 to 1577 cities. The experiments results indicate that Ge- GA has great robustness for TSP. For each test instance, the average value of solution quality, found in accepted time, stays within 0. 001% from the optimum.
文摘针对传统遗传算法(genetic algorithm,GA)求解旅行商问题(traveling salesman problem,TSP)存在寻优效率低、实验结果缺乏一致性等问题,提出了一种基于基因库的遗传算法(genetic algorithm based on genes pool,GPGA)。GPGA从种群中搜索减小哈密顿圈长度的边,并当做优良基因构成基因库。父代哈密顿圈在基因库引导下产生更优的子代哈密顿圈,基因库也随着种群的不断进化而同步更新,引导种群个体逐步向最优解靠近。算例结果表明在同样条件下,GPGA比传统遗传算法和几种改进遗传算法的性能更优。
