UV reflectance of inter-subspecific hybrid females obtained by crossing cabbage butterflies from Japan (Pieris rapae crucivora) with those from New Zealand (P. rapae rapae)

Cross-mating was performed between subspecies of cabbage butterfly Pieris rapae crucivora from Japan and P. rapae rapae from New Zealand, whose females are known to reflect and absorb ultraviolet (UV) light, respectively. In the female F ₁ hybrids UV reflectance was intermediate between the two parent females. Further, the UV reflectance was significantly higher in the female F ₁ hybrids derived from females of the New Zealand subspecies than in those derived from females of the Japanese subspecies.     

Progress in research and development on hybrid rice: a super-domesticate in China

BACKGROUND: China has been successful in breeding hybrid rice strains, but is now facing challenges to develop new hybrids with high-yielding potential, better grain quality, and tolerance to biotic and abiotic stresses. This paper reviews the most significant advances in hybrid rice breeding in China, and presents a recent study on fine-mapping quantitative trait loci (QTLs) for yield traits. SCOPE: By exploiting new types of male sterility, hybrid rice production in China has become more diversified. The use of inter-subspecies crosses has made an additional contribution to broadening the genetic diversity of hybrid rice and played an important role in the breeding of super rice hybrids in China. With the development and application of indica-inclined and japonica-inclined parental lines, new rice hybrids with super high-yielding potential have been developed and are being grown on a large scale. DNA markers for subspecies differentiation have been identified and applied, and marker-assisted selection performed for the development of restorer lines carrying disease resistance genes. The genetic basis of heterosis in highly heterotic hybrids has been studied, but data from these studies are insufficient to draw sound conclusions. In a QTL study using stepwise residual heterozygous lines, two linked intervals harbouring QTLs for yield traits were resolved, one of which was delimited to a 125-kb region. CONCLUSIONS: Advances in rice genomic research have shed new light on the genetic study and germplasm utilization in rice. Molecular marker-assisted selection is a powerful tool to increase breeding efficiency, but much work remains to be done before this technique can be extended from major genes to QTLs.     

水稻广亲和性遗传的再研究

水稻广亲和基因的利用是克服亚种间杂种不育性的重要途径。但在广亲和性的遗传上不同研究者的结论不尽一致。以3种有广亲和品种参加的三交组合为研究材料,研究了品种Ketan Nangka的广亲和性遗传。结果表明水稻亚种杂交F1同时存在着雄性不育和雌性不育,但雄性不育对小穗育性的作用大小因组合而异;无论是在雄性不育位点还是雄性不育位点上,Ketan Nangka均具有相对应的中性基因（广亲和基因）;广亲和性的遗传特点与所用的籼粳测验品种间的杂种不育性密切相关;S－5位点的广亲和基因遗传符合单位点孢子体－配子体互作模型。     

中国大陆地区白头鹎两个亚种的表型特征分析

选取体长、翅长、尾长、跗蹠长、嘴峰长、嘴宽、嘴高共7个量度指标,对在我国大陆地区分布的白头鹎Pycnonotus sinensis两个亚种共331号标本(指名亚种P.s.sinensis 239个,两广亚种P.s.hainanus 92个)进行了测量,运用统计软件SPSS 13.0对测量数据进行了比较分析,结果表明:指名亚种的翅长、跗蹠长、嘴宽和嘴高均大于两广亚种.指名亚种性别间的翅长、尾长、跗蹠长、嘴高和体长差异显著,而两广亚种性别间翅长、尾长、跗蹠长、嘴峰长和嘴宽差异显著,均是雄性个体大于雌性个体.将两个亚种的各量度性状与纬度进行相关分析,发现指名亚种雄性个体的体长与纬度呈弱的负相关,两广亚种的嘴高与纬度呈弱的正相关,其雄性个体的跗蹠长与纬度呈正相关.此外,对白头鹎指名亚种枕部白斑的宽窄度进行了等级划分并数量化,发现其宽度随季节而变化,在繁殖季节达到最大,支持其起饰羽作用的假说.