几种雄性不育玉米小孢子发育的显微荧光观察

采用高灵敏度的显微荧光术研究同一背景材料的细胞质不育和细胞核不衣小孢子发育过程，目的在于比较同核异质及同质近等系的小孢子发育过程，从中找出规律性的现象。结果表明，几种不育类型小孢子均表现核物质的降解，只是降解的时期不同。由此认为，雄性不育的细胞学实质就是细胞的自我降解。     

粗山羊草的细胞质对小麦抗旱性的影响

本文对具山羊草南（Ｄ型）的冬小麦核质杂种ＮＣ４、ＮＣ３７及其核共体亲本丰抗１２（细胞质为Ｂ型）在水分胁迫下的存活率、叶片相对含水量、细胞质膜透性、细胞渗透势等抗旱指标和叶算了细胞蛋白进行了检测，试验表明，粗山羊草细胞质能增加抗旱能力和影响叶片细胞蛋白质的表达，选育具有优良细胞质效应的质杂种小麦是改良小麦抗逆性的有效方法之一。     

W6154S×农垦58杂交后代育性转换株的发育感光性与育性转换特性

为了探讨水稻发育感光性与光、温敏雄性不育性之间的遗传关系,对W6154S/农垦58杂交组合F_2中发育感光性不同而具有明显育性转换特性的不育株及其衍生的F_3株系各单株进行了发育感光性与育性转换光温反应特性鉴定。结果表明:W6154S的育性转换特性可在发育感光性不同的背景中表达光敏不育性;所有F_2、F_3的育性转换株中没有分离出典型的温敏不育株;育性转换性状能在低世代稳定,而控制育性转换光温条件的遗传基础是复杂的。发育感光性强弱不是育性光敏性强弱的决定因子,育性光敏性强弱受遗传背景多因子综合作用,农垦58及其类似背景中可能存在增强光敏雄性不育主效基因表达的遗传因子。     

Characterization of the A4 cytoplasmic male-sterile lines of sorghum using RFLP of mtDNA

Three sorghum cytoplasmic male sterile lines CSV4 A(V), CSV4 A(G₁) and CSV4 A(M), grouped as A₄, were compared with a milo (A₁) and two other non-milo (A₂ and A₃) cytoplasms for their RFLP patterns of mitochondrial DNA (mtDNA). A 9.7 kb clone from pearl millet mtDNA discriminated each of the three A₄ entries whereas other maize and pearl millet mtDNA clones used could not distinguish this group completely. The molecular differences within the A₄ cytoplasmic group offer some explanation for the inconsistency in the fertility restoration behaviour of these A₄ lines obtained with a definite set of testers in the field. This revised version was published online in July 2006 with corrections to the Cover Date.     

矮败小麦群体改良的方法与技术

矮败小麦是具有矮秆基因标记的太谷核不育小麦. 根据轮回选择的基本原理和方法, 结合矮败小麦的特点, 我们逐步建立起一套简单易行的群体改良方法. 其主体技术包括组建一个好的基础群体, 利用控制授粉向群体引进优良基因, 通过开花前不良可育株的淘汰提高优良基因的频率, 借助于可育株与不育株的异交使基因重组, 以及正确地选     

三系杂交棉花粉育性对高温和低温胁迫的反应

为研究在高温和低温胁迫条件下的三系杂交棉花粉育性稳定性问题,利用棉花细胞质雄性不育系和恢复系,配制2个三系杂交棉组合,抗A×浙大强恢(记作：强恢F₁)和抗A×DES-HMF277(记作：弱恢F₁),并以保持系(抗B)为对照,分别进行温室控温试验和田间自然温度试验,分析三系杂交棉对高温和低温胁迫的反应和花粉育性转换(可育至不育)的临界温度。试验表明,一般三系杂交棉的花粉育性对胁迫温度的反应比保持系敏感,常常花粉散粉少和花粉活力较低。不同三系杂交棉组合对胁迫温度的抗性存在明显差异,强恢F₁明显高于弱恢F₁,与保持系的育性相似,可育花粉率和自交结铃率较高,不孕籽率较低。经可育花粉率(Y)与温度(T)的回归分析,花粉育性转换的临界温度符合Y = a (T–T_opt)²+b模型。强恢F₁育性转换的上限和下限温度分别为38.0℃和13.0℃,弱恢F₁为36.0℃和14.0℃,保持系为38.5℃和10.0℃。与低温胁迫比较,高温胁迫在我国大部分棉区更普遍,持续时间更长,对产量影响更大。提高三系杂交棉在胁迫气温条件下的花粉育性的稳定性是近期育种的重要目标。     

Season-specific varietal management as an option to increase rainfed lowland rice production in East African high altitude cropping systems

Due to land expansion and an increase in productivity, rice production in sub-Saharan Africa has been growing at a rate of 6% in the past decade. Rainfed rice production systems have accounted for a large share of this expansion. In these systems, the potential growing period not only depends on the length of the rainy season and thus water availability, but is often, especially in the highlands of East Africa, bordered by the onset of the cool period of the year, when low minimum temperatures compromise rice yields. The objective of this study was to investigate the yield potential of 30 rice varieties contrasting in crop duration and cold tolerance in the highlands of East Africa, with its limited length of growing period. A field trial was conducted in the cropping seasons in 2016 and 2017 at the Fogera rice research station, Ethiopia. As a function of the onset of rains, rice was sown mid-July in 2016 and early July in 2017. Early sowing in 2017 led to an extended crop duration and significantly lower yields of the short-duration varieties, and to a shortened duration and significantly higher yields of the medium- and long-duration varieties, when compared to late sowing in 2016. Late sowing compromised yield of the medium- and long-duration varieties because of low temperatures during booting stage, which led to high spikelet sterility. Early sowing resulted in low yields of the short-duration varieties, probably due to low solar radiation during the cloudy rainy season, which coincided with the vegetative stage. Therefore, choice of variety should be a function of the variable onset of the rainy season and related sowing date. However, crop models precisely calibrated for potential varieties and the respective environmental conditions could fully support the selection of a suitable variety, depending on the date of sowing, for example with the help of online tools or smartphone applications.     

Mitochondrial genome variation in Allium ampeloprasum and its wild relatives

Limitation in mitochondrial genome diversity of leek, revealed by restriction fragment length polymorphism (RFLP) analyses with mitochondrial gene probes, prevent a cytoplasmic male sterility (CMS) system in elite populations. However, mitochondrial genome diversity was detected in Allium ampeloprasum L. wild accession and landraces, as well as in pearl onion. Within this plant material, nine mitotypes were distinguished and could be used in order to broaden the genetic basis of leek. A chimeric mitochondrial gene configuration is usable as a marker for the sterility inducing cytoplasms (S₁) in chives (Allium schoenoprasum L.) and in onion (Allium cepa L.) for (S) and (T) cytoplasm. This chimeric mitochondrial gene configuration is also present in the subgenus Allium, revealed by polymerase chain reaction (PCR). However, only a faint amplicon was observed in a few accessions investigated herein, suggesting that this fragment might be present to a lesser level in mitochondrial DNA, as a sublimon.     

Identification of AFLP fragments linked to one recessive genic male sterility (RGMS) in rapeseed (Brassica napus L.) and conversion to SCAR markers for marker-aided selection

117AB is a recessive genic male sterility (RGMS) line in which the sterility is controlled by a duplicate recessive gene named ms, located at two separate loci. In the RGMS line, the genotype of the sterile plant (117A) is msmsmsms, and that of the fertile plant (117B) is Msmsmsms. The present study was aimed to identify DNA markers linked to the ms locus by amplified fragment length polymorphism (AFLP). From the survey of 512 AFLP primer combinations, 6 AFLP fragments (y1, k1, k2, k3, k4, k5) were identified as being tightly linked to the Ms locus. The genetic distances between the markers and the Ms locus were all less than 8 cM, among which two fragments, designated as k2 and k3, co-segregated with the target gene in the tested population. Fragment k2 was successfully converted into a sequence characterized amplified region (SCAR) marker. The markers detected could be valuable in marker-assisted breeding of RGMS in Brassica napus.     

Molecular mapping of a dominant genic male sterility gene Ms in rapeseed (Brassica napus)

Rs1046AB is a genic male sterile two‐type line in rapeseed that has great potential for hybrid seed production. The sterility of this line is conditioned by the interaction of two genes, i.e. the dominant genic male sterility gene (Ms) and the suppressor gene (Rf). The present study was undertaken to identify DNA markers for the Ms locus in a BC₁ population developed from a cross between a male‐sterile plant in Rs1046AB and the fertile canola‐type cultivar ‘Samourai’. Bulked segregant analysis was performed using the amplified fragment length polymorphism (AFLP) methodology. From the survey of 480 AFLP primer combinations, five AFLP markers (P10M13₃₅₀, P13M8₄₀₀, P6M6₄₁₀, E7M1₂₃₀ and E3M15₁₀₀) tightly linked to the target gene were identified. Two of them, E3M15₁₀₀ and P6M6₄₁₀, located the closest, at either side of Ms at a distance of 3.7 and 5.9 cM, respectively. The Ms locus was subsequently mapped on linkage group LG10 in the map developed in this laboratory, adding two additional markers weakly linked to it. This suite of markers will be valuable in designing a marker‐assisted genic male sterility three‐line breeding programme.