芝麻隐性核不育保持系选育与基因型分析

芝麻隐性核不育两用系杂交制种时,母本行需人工拔除分离出的50%可育株,为解决这一难题,为芝麻杂种优势利用提供新途径,采用不同遗传背景的种质与芝麻隐性核不育两用系0176AB中的不育株0176A广泛测交,在不育株率超过60%的分离世代中选取大量可育株与不育株0176A成对杂交,同时将可育株父本自交,筛选F1不育株率逐步提高的组合和父本,经过多代测交、自交、系选、异地鉴定和基因聚合,历时13年基本育成对0176A雄性不育性状具有完全(高度)保持效果的新材料WB51220、WB7-1D及高不育系W0176A和全不育系W71A。遗传测验表明,保持系WB7-1D的基因型为msms+rf_1rf_1rf_2rf_2…rf_ir_fi。两用系、保持系和恢复系可以实现芝麻隐性核不育三系配套,利用这种方法首次选育出芝麻核雄性不育三系杂交种皖芝6号(W0176A×皖芝1号F_1)和皖芝11号(W71A×皖芝2181F_1),产量分别比全国对照品种豫芝4号增产8.27%和23.0%。     

滇一型不育系黎输A高产繁殖技术

黎榆A是云南农业大学利用滇榆 1号A× (黎明×滇榆 1号 )育成的育性稳定、配合力较强、农艺性状优良的籼粳交偏粳型的滇一型不育系 ,介绍了黎榆A的特征特性 ,总结了单产超过 3 .75t hm2 的高产繁殖技术     

中国农科院油料所获得一批白、黑芝麻雄性核不育系

自 1 996年武汉市科委下达芝麻雄性不育选育课题后 ,油料所的芝麻核不育选育及其配套技术列入重点攻关项目。根据芝麻高产、优质、多抗的育种目标 ,对杂交芝麻种豫芝 9号分离出来的不育株 ,进行针对性地转育。现已获得白芝麻核不育系 40份 ,其中有 9份不育率连续 3代稳定在 50 %左右 ,代表系有 :97( su.c.W ) ms36,97( su.c.W) ms40 ;黑芝麻核不育率稳定在 50 %左右的有 2 9个株系 ,其中 97( su.c.B) ms0 1性状稳定。用上述不育系所配制的杂优组合 ,在 1 999年测产试验 (小区面积 1 3m2 ,3次重复 )中 ,白芝麻6个组合均比同类型的杂交种增…     

高粱新型细胞质雄性不育系A3180A的选育

利用高粱非迈罗细胞质A3TX398为不育源,以铁恢180为基础材料经连续6代回交转育,于2004年育成新型细胞质雄性不育系A3180A,试验与研究结果表明:该系具有育性稳定,配合力高,综合农艺性状优良等特点,为高粱杂交种的选育开辟了新途径,对A1、A2型保持系的提前测定提供了有效方法.     

甘蓝型油菜无花瓣品系雄蕊雌化不育系的发现和遗传研究

1998年在自选的甘蓝型无花瓣油菜株系中发现了一种突变不育株,进而育成无花瓣油菜突变不育系(简称AMS).经连续4年研究,结果表明:该雄性不育系不育性彻底,是一种雄性器官雌性化而引起的新的不育现象,其植株形态特征与无花瓣相同.用来自国内外不同品种(系)和胞质雄性不育系的保持系、恢复系及杂种F1共549份材料配制了779个杂交组合,全部恢复育性.2002和2003年收获的100个杂交组合有29份较对照(秦优7号杂交种)增产5.7%～23.5%,达显著水平.该突变不育株与可育株测交,后代不育和可育符合1:1的遗传分离模式,经对AMS测交、杂种自交,表明不育性很可能由4对隐性基因控制.     

芝麻杂交制种技术研究Ⅰ：亲本行比与产量的关系

为获得理想的父母本行比,增加芝麻杂交种的制种产量,以芝麻隐性核雄性不育系1615A为材料,开展 了不同亲本行比与产量关系的研究。结果表明：（1）在父母本行比为1:10、2:10、3:10、4:10和5:10的试验中,在授粉 不够充分的情况下,母本（不育系）不育株表现出非正常成熟和基部无效分枝的异常植株生长形态,且非正常成熟 植株比率和基部无效分枝植株比率随着距离父本的行数增加而增加,和与父本距离呈极显著正相关,而和父本行 数的关系较小,在与父本邻近的1~3行或1~4行的不育系植株中非正常成熟植株比率和基部无效分枝植株比率均 相对较低;父本行数、与父本距离对母本的每蒴粒数和单株产量影响最为显著,父本行数和单株产量呈极显著正相 关,与父本距离和每蒴粒数、单株产量呈极显著负相关,随着与父本距离的增加而减少,在与父本邻近的1~3行或 1~4行的母本植株每蒴粒数和单株产量均相对较高。可见,芝麻父本花粉在邻近的3~4行母本植株上可以得到高 效传播,使不育系植株得到较充分的授粉。（2）在父母本行比为1:2、1:3、1:4、1:5、1:6和1:7的6个试验组合中,母本的 每蒴粒数和单株产量均表现为逐渐减少,理论产量表现为先上升后下降,在1:5时达到最高;在2:4、2:5、2:6、2:7、2:8、 2:9和2:10的7个试验组合中,母本的每蒴粒数和单株产量同样逐渐减少,理论产量也先上升后下降,在2:6时达到 最高;综合试验结果认为,芝麻隐性核不育杂交种制种的父母本行比为1:4、1:5和2:6、2:7,制种的理论产量分别为 425.54 kg/hm2、429.30 kg/hm2和473.61 kg/hm2、469.23 kg/hm2。     

棉花光温敏核不育系396A育性特征及杂种优势分析

棉花光温敏核雄性不育系396A是从海陆杂种后代中发现的具有芽黄标记性状的新型核雄性不育系。为探明该不育系在不同温度和光照条件下的育性表现及其杂种优势表现,分别在新疆博乐和三亚海棠湾进行试验,研究了该不育系的育性变化及其杂交种的产量性状、抗病性、纤维品质。结果表明:棉花光温敏核雄性不育系在三亚种植可正常恢复育性,且花粉量大,自交成铃率高,能够自然繁殖;在博乐表现为雄性不育,没有花粉,自交成铃率为0,不育度100%,且配合力好,恢复源广阔,恢复能力强,可作为母本进行杂交制种;其杂交种F_1代育性恢复好,花粉量大,全部能够自然成铃且杂种优势明显,其中,部分杂交种产量高、抗病性好、纤维品质优良,表现出较强的杂种优势。     

高粱新型细胞质雄性不育系A_3180A的选育

利用高粱非迈罗细胞质A3TX398为不育源,以铁恢180为基础材料经连续6代回交转育,于2004年育成新型细胞质雄性不育系A3180A,试验与研究结果表明:该系具有育性稳定,配合力高,综合农艺性状优良等特点,为高粱杂交种的选育开辟了新途径,对A1、A2型保持系的提前测定提供了有效方法。     

甘蓝型油菜隐性核不育系20118A的遗传与利用探讨

测交试验分析表明，甘蓝型油菜（Brassica napus L.)核不育系20118A的不育性由2对隐性重叠基因和1对隐性上们基因控制，具有广泛的恢复系。当2对基因为隐性纯合体（aabb)，另1对互作基因为显性（RfRf或Rfrf)时，植株表现不育（aabbRfRf或aabbRfrf），其相应临保系的基因型为3对隐性纯合体（aabbrfrf）。两型系中不育株与可育株连续兄妹交和可育株连续自交，后代可育株和不育株育性分离比分别为1：1和3：1，利用纯合两型系 AabbRfRf或aaBbRfRf中不育株和可育株成对兄妹交可生产纯合两型系和不育系20118A，不育系和临保系杂交生产全不育系（aabbRfrf），全不育系与恢复系（AA-或-BB）杂交生产杂交种，从而使隐性核不育系20118A应用于生产。     

油用向日葵新葵19号不育系1193A的选育及利用

为了选育新的向日葵不育系,通过研究油用向日葵不育系的选育方法。对现有技术中向日葵自交系选育过程中连续自交多代,基因重组机率太小的现状,改变保持系从杂种一代F1以后连续自交的作法,进行了在F2和F3代2次姊妹交的研究,提高了保持系基因重组的机率,加大了选育出优良不育系的机会,为强优势杂交种后备品种选育奠定坚实的亲本基础。选育出油用向日葵新葵19号不育系1193A,该不育系植株性状好、抗病性好、抗逆性强、配合力高、杂种优势强。该研究提供了一种油用向日葵不育系新的选育方法,并对不育系1193A进行利用。     

SILAGE AND MILK PRODUCTION. A COMPARISON BETWEEN A DIPLOID AND A TETRAPLOID RYEGRASS

Two grass silages made in May and two made in August were compared in a 16-week winter-feediag experiment with 12 Ayrshire cows. The silages were fed ad lib. with a supplement of barley and groundnut cake. One of the silages made ia May and one made in August consisted of S24, a diploid variety of perennial ryegrass, and the other two of Reveille, a tetraploid variety of the same species. The silages made from Reveille had a higher content of lactic acid and a lower pH than those made from S24. The contents of digestihie organic matter in the silage DM made in May and August were 71.9 and 63.2%, respectively, for RevelUe and 68.7 and 60.9% for S24. Silage and total DM intakes were higher in the treatments where Reveille silages rather than S24 silages were fed. The mean daily milk yields from cows fed on the silages made in May and August were 39.6 and 34.5 lb (18.0 and 15.7 kg), respectively, for Reveille, and 38.0 and 34.1 lb (17.3 and 15.5 kg) for S24. The solids-not-fat (S.N.F.) and the crude protein contents of the milk averaged 8.64 and 3.29%, respectively, for Reveille, and 8.56 and 3.22% for S24. It is concluded (hat the silages made from Reveille were superior to those made from S24 as a feed for dairy cows.     

A LINEAR PROGRAMMING MODEL OF A HIGH-TEMPERATURE GRASS-DRYING ENTERPRISE

A linear programming model of a high-temperature grass-drying enterprise is described. From information about seasonal crop response, area of crop available and management constraints, the model determines the harvesting schedules which give greatest returns, less costs, from the enterprise over the season. This information can be used to examine the effects of long-term strategic decisions or to evaluate economically data on new crops from field experiments. For example, assuming a fixed cost of λ70,000/year for a high-temperature grass-drying installation and what is considered to be reliable input data for 1972, the returns less costs for optimum harvest schedules from different areas or crop varieties are:

Development of A dormancy release technology: A review

Tuber dormancy can be released immediately in many commercially important potato cultivars by brief treatment (1-2 days) with bromoethane (BE) vapor at room temperature. The development of a large scale technology for BE application and safe removal through a capturing technique is necessary for successful application of this dormancy release method. Ideally, BE treatment of seed tubers would occur in a closed environment that would capture BE vapor in an unaltered form and allow controlled release for treatment of subsequent tuber lots. Results of screening studies for adsorbents indicate that the medium capacity activated carbon adsorbent, YAO has: i) a high capacity for BE; ii) a low capacity for water; and, iii) adsorbs and de-adsorbs BE quickly and easily. A plausible design of a large scale, dormancy release facility is presented. The proposed facility should meet present goals of the seed potato industry in an environmentally responsible manner.     

A MANAGEMENT STUDY OF A BIRDSFOOT TREFOIL STRAIN TRIAL

A study of birdsfoot trefoil ( Lotus corniculatus L.) variety trial management was conducted with three variables, variety, stubble height and harvest date. The range in maturity for the three varieties used was 12-14 days. All plots were harvested thrice per season. The harvest dates for the two management regimes imposed differed by about two weeks for the first cut, by about one week for the second and were identical for the third cut. Stubble heights were two and six inches (5.08 and 15.24 cm).
Late-cut material outyielded that cut early, but suffered more winter damage. Material cut at a stubble height of two inches (5.08 cm) outyielded that cut at six inches (15.24 cm), but it also suffered more winter-killing. The ranking of varieties varied with management.
Alternative management schemes, designed to provide maximum yields and survival consistent with good-quality forage, are proposed and discussed.     

A COMPARISON BETWEEN A PADDOCK SYSTEM AND A 'WYE COLLEGE' SYSTEM OF GRAZING FOR MILK PRODUCTION

Two grazing systems, a paddock system and a ‘Wye College’ system, were compared in two 20-week experiments nsing 16 and 20 spring-calved Ayrshire cows in 1970 and 1971, respectively. A sward of S23 perennial ryegrass was used, and an average of 342 kg N/ha (305 lb N/ ac) was applied per annum. The paddock system had 28 separate paddocks; one paddock was grazed each day in rotation and occasionally topped in mid-season. The Wye College system had 4 plots of equal size and the cows were offered 1/7 of one plot each day; no back fence was used and surplus herbage was neither cut nor topped. The stocking rate on hoth systems was 1 cow per 0.20 ha (0.49 ac) in 1970 and per 0.16 ha (0.40 ac) in 1971. The mean daily milk yields per cow on the paddock and the Wye College systems were 16.2 and 15.3 kg (35.7 and 33.7 lb), respectively, in 1970; and 18.1 and 18.4 kg (39.9 and 40.6 lb) in 1971. The average annual output of milk was 13,500 and 13,150 kg/ha (1200 and 1170 gal/ac) on the paddock and Wye College systems, respectively. The fat and solids-not-fat (S.N.F.) contents of the milk were not significantly affected by the grazing system. It is concluded that the Wye College system was as effective as the paddock system in producing a high output of mUk per ha, but at a lower cost and with far fewer management decisions.     

广东育成无垩白软型优质籼稻不育系粤丰A

粤丰Ａ是由广东省农科院水稻研究所于1998年育成的国内第一个无垩白、低直链淀粉含量(14.3%)、软胶稠度(92ｍｍ)、低糊化温度(碱消值7.0)和香味浓的特优籼型三系不育系。该不育系千株群体不育株率为100%,花粉不育度为99.99%,柱头外露率达88.1%,稻瘟病全群抗性比达中抗水平。2000年10月在广州通过了由来自扬州大学、国家水稻改良中心、国家杂交水稻工程技术研究中心等单位著名专家的技术鉴定。专家组一致认为该不育系综合性状优良、不育性稳定、配合力强、异交结实率高、品质改良有重大突破,研究成果达国内外领先水平;其投入生产应用对推动我…