流式细胞仪测定百合花粉倍性的研究

[目的]为利用百合未减数花粉进行有性多倍化育种。[方法]利用流式细胞仪测定百合花粉的倍性,以Marlon、Viviana的花粉为材料,以叶片为对照,比较两种不同细胞核提取液的效果差异。[结果]Cy Stain UV Precise T提取液明显优于WPB提取液;Marlon、Vivian叶片测定结果显示其为二倍体,花粉测定的图像显示两个品种都能自发产生2n花粉。[结论]流式细胞仪可以快速地测定百合花粉的倍性。     

中国西北地区内陆盐湖卤虫染色体倍性 组成的研究

本文研究了新疆维吾尔自治区（简称新疆）、青海省和内蒙古自治区（简称内蒙古）19个卤虫品系的染色体倍性组成。其中属于两性生殖类型的卤虫有13个品系，孤雌生殖类型的卤虫有6个品系。13个行两性生殖品系的染色体为：二倍体，2n＝42，6个行孤雌生殖品系的染色体，既有二倍体2n＝42，又四倍体，4n＝84和五倍体，5n＝105。一部分细胞的染色体表现非整倍的特点。     

多因素对秋水仙素诱导多倍体效率的影响

[目的]明确各因素对秋水仙素诱导效率的影响。[方法]通过正交试验,研究秋水仙素浓度、紫外线辐射单次时长及频数、温降单次时长及频数对秋水仙素诱导刺槐多倍体效率的影响。[结果]紫外辐射时长对秋水仙素诱导效率的影响最显著,80 s时膨大率最高,其次是浓度。各浓度组间膨大率呈周期性变化,随浓度增加整体略有上升。辐射频数和温降频数对膨大率的影响较小,分别以2、1次最好。温降时长以5 min最佳。不同辐射时长和不同辐射时间点的诱导效果有明显差异。单纯的紫外辐射不能诱导根尖膨大细胞加倍,不能降低秋水仙素的最低有效诱导浓度。单次剂量2 min出现抑制效果,4 min出现明显的生长抑制,8 min生长停止。[结论]最优组合是0.3%秋水仙素,辐射40 s共2次,温度骤降5 min共1次。     

Ploidy and growth performance of hybrid progeny between tetraploid Misgurnus anguillicaudatus and Paramisgurnus dabryanus

Experimental crossings were made between tetraploid loach (Misgurnus anguillicaudatus, T for short) and diploid large‐scale loach (Paramisgurnus dabryanus, P for short), resulting in T×T, T×P and P×P crosses (female before male). Meanwhile, a part of T×P cross was cold shocked to inhibit second meiosis (T×P‐0 for short). Fertility rate, hatching rate and survival rate of T×T, T×P, P×P and T×P‐0 were measured. Flow cytometry and chromosome count were taken to identify ploidy statuses of the four crosses. Results showed that T×T, T×P and P×P were, respectively, tetraploidy (4n = 100), triploidy (3n = 74) and diplody (2n = 48), while 89.19 per cent of T×P‐0 of 12 months old were pentaploidy (5n = 124, T×P‐0‐5n for short) and the others were triploidy. Morphological data of the four crosses of 12 months old showed that morphological characteristics of T×P and T×P‐0‐5n loach were between those of their parents, while T×P‐0‐5n loach presented a smallest head length/body length. Total lengths of T×P and T×P‐0‐5n were significantly larger than those of T×T and P×P, showing hybrid vigour. This study will provide valuable information for production of polyploidy loach and breeding programmes of the two loaches and other closely related species.