【目的】孔雀草(Tagetes patula)是菊科万寿菊属一年生花卉,具有很高观赏价值和经济价值。优势育种是培育草花新品种的重要途径。本研究探究四倍体孔雀草优势育种后代是否具有杂种优势,并分析其遗传效应,为孔雀草的优势育种提供理论依据。【方法】对孔雀草6个母本(K2、K3、K4、K5、K15、K17)和3个父本(K6、K8、K13)采用NCII不完全双列杂交设计,并测量亲本和18个杂交组合的始花期、盛花期、株高、冠幅、分枝数、花朵数、花葶长、花径、花心径、舌状花数和管状花数等11个园艺性状。利用Excel软件对后代园艺性状进行杂种优势分析;利用DPS软件分析后代园艺性状的配合力和遗传力,选出优良亲本和杂交组合,并进一步分析其遗传表现。【结果】杂种优势分析表明,冠幅、花朵数、花径的超亲优势为正值;盛花期、株高、舌状花数的中亲优势为正值;始花期、分枝数、花葶长、花心径、管状花数的超亲优势和中亲优势均为负值。根据各亲本的一般配合力效应值表明:K6可用作培育低矮、紧凑、多花品种的父本;K13可用作培育早花、大花、复瓣和较长观赏期品种的父本;K3可用作选育株型紧凑、早花、复瓣和较长观赏期品种的母本;K5可用作培育低矮、紧凑、早花、多花和较长观赏期品种的母本;K17可用作培育低矮、大花和复瓣品种的母本。特殊配合力分析表明,同一亲本所配组合之间以及同一组合不同的园艺性状间的特殊配合力效应值差异很大。K2×K6和K3×K8在株高、花心径上特殊配合力表现出较强的负向效应,在花朵数、舌状花数上表现出较强正向效应,符合孔雀草低矮、多花和复瓣的育种目标;K4×K13在始花期、株高、冠幅、分枝数上特殊配合力表现出较强负向效应,在盛花期、花径、舌状花数上表现出较强正向效应,适合培育株型紧?
【Objective】Tagetes patula belongs to Tagetes genus of the Asteraceae family and it is an extremely popular annual plant for its great commercial and ornamental value. Heterosis breeding is an important approach to breed new cultivars. The heterosis and the genetic effects of horticultural traits of F1 hybrids of tetraploid T. patula were analyzed to establish a heterosis breeding system. 【Method】 Eighteen cross combinations of T. patula were made using six inbred lines K2, K3, K4, K5, K15, and K17 as female parents crossed with three male parents K6, K8, and K13 by following the North Carolina Design II incomplete diallel cross design method, then eleven horticultural traits of first flowering date, full-bloom stage, plant height, crown size, branch number, inflorescence number, pedicel length, diameter of inflorescence, diameter of disk florets, and number of ray florets, number of disk florets were investigated. Heterosis of horticultural traits was calculated using Excel software and combining abilities and heritabilities were analyzed using DPS software to chose primary parents and excellent combinations. 【Result】 The results of heterosis analysis showed that the crown size, number and diameter of inflorescence were improved over best parent and the full-bloom stage, plant height and ray floret number were improved over mid-parent, but the traits of first flowering date, branch number, pedicel length, diameter of disk florets and number of disk florets conferred negative best parent and mid-parent values. Analysis of general combination ability(GCA) showed that the line K6 was chosen as the preferred male parent due to the dwarf, compact and multiple flower traits conferred to the hybrid progeny; the line K13 was judged to be a good male parent for the production of hybrids with early flowering, large and double flower and long ornamental period; the line K3 was the preferred female parent for the production of hybrids of compact plant, early flowering, double flower and long ornamental period