茄子早熟育种研究Ⅱ选择指数与早熟性选择

研究结果表明,由性状果实最大周长,果实体积,门茄显蕾期,单株产量等性状构成的选择指数较好;进一步进行遗传相关分析结果认为,应用选择指数时应注意果实体积这个性状,单株产量是一个重要的辅助性状,门茄显蕾期是一个限制性因子。应用选择指数对品种评价结果认为,早熟性较好的品种有:天津早茄、西安绿茄、二民、七叶茄、白线茄和汉中荷包。     

Simulating farming practices within a region using a stochastic bio-decisional model: Application to irrigated maize in south-western France

Agricultural is a major contributor to environmental resource management problems. Modelling the distribution of agricultural land use to evaluate current situations or scenarios is an important issue for policy-makers and natural resource managers. A promising approach is the use of bio-decisional models based on decision rules. However, at the regional scale, the large number of farmers makes it difficult to identify decision rules, and the diversity of farmers' decisions is rarely considered. To this end, we developed SIMITKO, a spatialised and stochastic bio-decisional model, able to simulate the spatial and temporal variability in farming practices. We focused on the choice of varietal earliness and sowing practices of maize (Zea mays L.) in the Baïse sector (south-western France). Model development was based on statistical analyses of surveys of farmers’ practices to identify their current strategies, the best variables to describe the practices and the probabilities associated with the values of the variables for each strategy. We tested SIMITKO by simulating the dynamics of areas sown with maize. Comparing model predictions of practices to observed data showed generally good predictions of sowing dynamics but less satisfactory predictions of varietal earliness choices. Possible improvements are suggested.     

短季棉早熟性状及产量构成因素的遗传分析和选择策略

对9个早熟及产量性状的有关遗传参数进行了相关分析和通径分析,结果表明,高强度选择可使目前推广品种(系)的丰产性和早熟性得到进一步改善;育种选择策略应从提高株铃数和衣分入手,选择第一果枝节位低、开花早、脱落少和铃不太大的类型,其中早代果枝节位严选,开花期、结铃率和衣分大群体选择,株铃数连续选择,就可实现培育出高产、早熟品种(系)最终目标.     

Analysis of photoperiod sensitivity within a collection of tropical maize populations

We analyzed the variability of a large maize (Zea mays L.) collection of152 tropical populations for photoperiod sensitivity and grain productivityunder long-day conditions to investigate their potential adaptation to temperateconditions. A multilocal experimental design was used: one location withshort-day conditions (Guadeloupe), one location with medium-day conditions (latesowing in the south of France) and two locations with long-day conditions (earlysowing in both the North and South of France). The photoperiod sensitivity wasestimated by the slope of the regression of thermal time from sowing to 50%anthesis on photoperiod. We found highly significant effects of latitude andaltitude of the collecting site of the population on photoperiod sensitivity anda significant but small interaction between these two factors. Populationsoriginated from low altitudes and low latitudes are highly sensitive tophotoperiod, whereas highland populations never display a high photoperiodsensitivity, whatever the latitude of origin. Grain productivity under long-dayconditions was not highly correlated with photoperiod sensitivity. Andeanpopulations were little sensitive to photoperiod and exhibited poor grainproduction under long-day conditions. In contrast, some populations from theCaribbean such as populations from Cuban Flint and Early Caribbean racesexhibited a good grain production although sensitive to photoperiod. The goodadaptation of some Caribbean material to temperate conditions is consistent withthe hypothesis of the successful introduction of Caribbean germplasm in southernregions of the Old World.     

秋早熟大白菜品种比较试验

对7份来自不同地区的早熟大白菜品种进行露地种植,小区比较试验表明,新早56每666.7m2净菜产量最高,达4 934.56 kg,其次为华良夏秋,为3 829.07 kg,两品种抗病性强,生育期分别为62天和68天,适合当地秋早熟栽培;巨龙早秋和潍白6号虽单株产量最高,但黑腐病发生严重,影响产量;津绿55作为直筒类型,可加以密植,提高产量。     

Identification and Gene Mapping of Completely Dominant Earliness in Rice

The completely dominant earliness was identified in a genic male-sterile and early maturing indica line 6442S-7. F1 progenies from 6442S-7 crossed with thirteen various types of medium- or latematuring varieties, shared the same heading date as 6442S-7. The segregation of heading date in the F2 and B1F1 populations showed that the earliness of 6442S-7 is mainly controlled by two dominant major genes. The local linkage map of one dominant earliness gene harbored in 6442S-7 was constructed with F2 population and four kinds of molecular marker techniques. The results showed that the gene was located between a RFLPmarker C515 and a RAPD marker OPI 11. 557 on the terminal region of short arm of rice chromosome 3,10.9cM and 1.5 cM from C515 and OPI11. 557, respectively. The genetic distances from the target gene to twoSSR markers, RM22 and RM231, and one AFLP marker, PT671, were 3.0, 6.7 and 12.4 cM, respectively. This gene, being identified and mapped first, is designated tentatively as Ef-cd (t). As a new genetic resource of completely dominant earliness, 6442S-7 has splendid future in rice improvement.     

Mapping chromosomal regions affecting flowering time in a spring wheat RIL population

Flowering time is an important trait for the adaptation of wheat to its target environments. To identify chromosome regions associated with flowering time in wheat, a whole genome scan was conducted with five sets of field trial data on a recombinant inbred lines (RIL) population derived from the cross of spring wheat cultivars ‘Nanda 2419’ and ‘Wangshuibai’. The identified QTLs involved seven chromosomal regions, among which QFlt.nau-1B and QFlt.nau-2B were homoeologous to QFlt.nau-1D and QFlt.nau-2D, respectively. Nanda 2419, the earlier flowering parent, contributed early flowering alleles at five of these QTLs. QFlt.nau-1B and QFlt.nau-7B had the largest effects in all trials and were mapped to the Xwmc59.2–Xbarc80 interval on chromosome 1BS and the Xgwm537–Xgwm333 interval on 7BS. Most of the mapped QTL intervals were not coincident with known vernalization response or photoperiod sensitivity loci and QFlt.nau-1B seems to be an orthologue of EpsA ^m 1. Four pairs of loci showed significant interactions across environments in determining flowering time, all of which involved QFlt.nau-1B. These findings are of significance to wheat breeding programs.     

Genetic mapping of a new flowering time gene on chromosome 3B of wheat

The single chromosome substitution lines of chromosome 3B of the Czech alternative wheat variety Česká Přesívka (CP 3B) into two spring varieties Zlatka and Sandra, revealed clear differences in flowering time compared to the recipient varieties. To map this gene(s), recombinant substitution lines for chromosome 3B were produced from crosses of the substitution lines with their recipient parents and genetic maps developed using SSR markers. Two populations were mapped, Sandra//Sandra 3B/Sandra (CP 3B) and Zlatka//Zlatka/Zlatka (CP 3B). Combining the genotype data with phenotype data on flowering time in five independent experiments under natural long day or controlled short day conditions revealed a single flowering time QTL. This gene had an additive effect of 1–6 days, depending on environment and genetic background, and was mapped in both populations to a position in the region of marker Xbarc164 near the centromere on the long arm of 3B. Comparisons of the genetic maps with other 3B maps developed by the authors indicated that the QTL may be homologous to a QTL segregating in UK germplasm.     

优质、早熟、抗病菜用大豆新品种"青酥四号"的选育

“青酥四号”是采用有性杂交和系统选育方法育成的新品种,母本从亚洲蔬菜研究发展中心引进,父本从上海地方毛豆品种“牛踏扁”中系选获得。经对2份种质材料有性杂交后代连续8代的定向系统选育,于F8决选品系21-11。在2002~2003年江苏省鲜食大豆区域试验中,该品系表现早熟,较对照“台292”早上市4 d,鲜荚平均产量529 kg/666.7 m2,比对照“台292”减产2.8%,未达显著水平;鲜粒平均产量265.16 kg/666.7 m2,比对照增产6.55%;鲜豆出仁率达55.2%,较对照高。该品种于2005年2月分别通过上海市和江苏省农作物新品种的审定,在苏浙沪皖地区累计示范面积达1 000 hm2以上。     

抗病、优质、早熟大白菜"早心白"的选育

早心白是河北省农科院经济作物研究所(原蔬菜花卉研究所)培育的抗病、优质、早熟的大白菜杂交一代新品种。生长期58 d,株高45 cm,叶长40 cm,宽25 cm。外叶绿,成熟时似莲花状,叶球合抱,心叶白绿,鲜嫩,纤维少,适口性好。叶球重2 kg,净菜率75%,一般产量5 000~6 000kg/hm2。高抗病毒病、软腐病,耐热,是我国北方秋早熟大白菜种植的理想品种。