杂交油菜种子质量试验及分级问题探讨

对杂交油菜种子进行科学的质量分级，是当前种子生产和质量管理方面急待解决的问题，通过试验研究认为，对于育成时间短，应用面积小的杂种组合进行种子质量分级，条件尚不成熟。但对推广时间长。面积大，质量比较稳定的质不育“三系”和核不育“两系”杂交组合制定种子质量标准则是可行的。该文依据试验结果，探讨了质不育“三系”和核不育“两系”油菜杂交种种子质量的分级问题。     

Response of Rapeseed (Brassica napus L.) Growth, Yield, Oil Content and Its Fatty Acids to Nitrogen Rates and Application Times

A steady and progressive increase in rapeseed yield was observed with each increment in applied nitrogen rates up to 213 kg/ha in both seasons. As for nitrogen application times, the analyzed data showed that adding a split dose (either 1/2 or 1/3) before the third irrigation was a common part between high yielding treatments in 1985/86 season. Nitrogen rates X application times interaction affected rapeseed yield significantly during the first winter season. The highest seed yield of 2.5 t/ha was obtained by adding 213 kg N/ha in two split doses at sowing and just before the third irrigation. The second yield value of 2.47 t/ha was produced under the same N rate when applied in two split doses before second and third irrigation. However, in the second season (1986/87), rapeseed plants did not exhibit significant responses to nitrogen rates X application times interaction.
Chemical analyses showed that rapeseed oil content and its fatty acids (Palmetic, Stearic, Oleic, Linoleic, Linolenic, Arachidic and Erucic) percentages were not significantly affected by either nitrogen rates or application times in both seasons. A very low content of Erucic acid (0.1–0.9 %) in all tested sample was noticed.     

Genetic variation for dry matter and nitrogen accumulation and translocation in two-rowed spring barley: I. Dry matter translocation

A 4-year field study was carried out to determine dry matter and nitrogen accumulation until anthesis and at grain filling period and dry matter translocation and utilization in grain filling of barley. Twenty two-rowed spring barley (Hordeum vulgare ssp. distichum L.) cultivars originated from different countries (Yugoslavia, Germany, Australia, the Czeck Republic, Netherlands, France and USA) were grown during 1995–1998 on a non-calcareous chernozem soil near Novi Sad (45° 20′N, 15° 51′E, 86 m asl). Dry matter and nitrogen accumulation depended on the cultivar and year. In a year with favorable weather conditions, 58% of dry matter was accumulated during pre-anthesis, while in a year with less favorable weather the amount was 48%. In the favorable year 91% and in unfavorable year 65% of nitrogen was accumulated until anthesis. The results indicated that the greater amount of dry matter and nitrogen accumulated before anthesis. Dry matter translocation efficiency depended on the cultivar and ranged from 3 to 16.4%, while the contribution of pre-anthesis assimilates to kernel varied from 4 to 24.2%. Cultivars that have been developed for the growing conditions of the area where the experimental site was located, i.e. adapted ones, did not use pre-anthesis dry matter for grain filling. High positive correlations (P<0.01) were found between biomass at anthesis and biological yield, dry matter translocation efficiency, contribution of translocated dry matter to grain yield, and total plant nitrogen at maturity. Accumulated nitrogen at anthesis was positively correlated (P<0.01) with growing degree–days until anthesis, dry matter at anthesis and dry matter translocation parameters. Heritability for the investigated characters was rather high, over 0.60.     

不同品种春小麦硫、钙、镁吸收动态模型及分布运转的研究

以蒙麦36号等3个春小麦品种为材料,系统研究了S,Ca,Mg 3种养分在不同生育时期体内含量变化及分布运转规律;查明了其百公斤子粒吸收量,消耗系数,生产效率;建立了3个春小麦品种S,Ca,Mg养分的吸收动态模型。并应用模型理想地摸拟了最大吸收量、最大吸收速率及其出现时间。     

春小麦籽粒灌浆过程淀粉和蛋白质积累规律的初步研究

利用蛋白质含量和产量各异的３个春小麦品种，Ｒｏｂｌｉｎ、东农７７４２和新克旱９号，研究了灌浆过程中可溶性性糖、淀粉和蛋白质积累规律，结果表明：籽粒灌浆过程中可溶性糖含量由开花１４天开始逐渐减少，成熟期达最低值，品种间的差异仅表现以１４天和２０天两个时期：淀粉积累动态与可溶性糖变化规律相反，随灌浆成熟而逐渐增加，品种间差异达显著水平；蛋白质积累动态年际间稍有差异，总的趋势是随灌浆成熟而逐渐增加，开花     

不同矮秆基因小麦农艺性状的遗传差异

对含有不同主效矮秆基因（Ｒｈｔ１，Ｒｈｔ２和Ｒｈｔ１＋Ｒｈｔ２）的三组春小麦进行了两年，两地试验。结果表明，具有半矮秆基因Ｒｈｔ１的小麦表现出较高的生物产量，穗粒数和容重，它们以此获得较高的籽粒产量；具有矮秆基因Ｒｈｔ１和Ｒｈｔ２的小麦，则表现出较高的千粒重，通过半大收获指数获得高产；在两个半矮秆组内，籽粒产量与株高之间，粒数／ｍ＾２与千粒重之间均为显著负相关，就矮秆组而言，在籽粒产量与粒数／ｍ＾     

壳聚糖配以6-BA及PP333包衣种子对春性小麦冬前生长发育的影响

通过田间试验检测了壳聚糖（CHT）溶液及配入外源植物激素包衣种子对春性小麦冬前生长发育的影响。结果表明：用2％的CHT溶液包衣，能显著促进种子萌发及麦苗生长，配入50或100mg/L的6－BA，能明显增加单株分蘖及生物量。试验结果还表明：在2％的CHT溶液中，当PP333浓度为800mg/L时，配入50或100mg/L的6-BA对茎蘖生长发育没有增效作用，但最终均能使春性小麦形成苗壮、蘖多、抗寒性好的冬前群体；然而当PP333浓度为1200mg／L时，配入50或100mg／L的6－BA有明显的增效作用，并最终也形成苗壮、蘖多、抗寒性好的冬前群体。     

体细胞杂交在油菜细胞质雄性不育创建和改良中的应用

油菜细胞质雄性不育作为生产油菜杂交种的主要授粉控制系统得到广泛利用，但由于油菜种内自然发生的有利用价值的雄性不育细胞质类型不多，所以种属间转移现有不育细胞质及发掘新型不育细胞质意义重大。体细胞杂交不仅避开了有性杂交亲和障碍的限制，还可实现两个杂交亲本细胞质基因组的重组，是一种快速有效、应用广泛的转移和诱导雄性不育细胞质的手段。本文综述了利用原生质体杂交技术在油菜种内、种间和属间转移雄性不育细胞质以及通过细胞质基因组重组改良和创建新型雄性不育细胞质的研究进展，并讨论了利用体细胞杂交方法创建新型雄性不育细胞质的应用前景。     

Components of a Cytoplasmic Male Sterility System in Resynthesized and Cultivated Forms of Oilseed Rape (Brassies napus L.)

Male sterile Brassica napus L. plants were found in breeding material which was used for the development of yellow-seeded oilseed rape. The genetic studies indicated that the male sterility was conditioned by the presence of maintamer genes in the nuclear backgrounds of two newly resynthesized B. napus lines, No7076 and No7406, in combination with a male sterility-inducing cytoplasm (S) which is frequently found in cultivated forms of B. napus. Test crosses with nap maintainer and restorer lines support the conclusion that the observed male sterility is of nap type. Furthermore, the Eco RI restriction pattern of mitochondrial DNA of the (S) cytoplasm was identical to that of the nap cytoplasm. Hence, we conclude that we have uncovered a new source of maintainer lines for the nap system which could potentially lead to the production of a better maintainer/restorer system for use in hybrid oilseed rape breeding programmes. However, more work is needed to reduce the glucosinolate content of the maintainer lines and to determine the factors controlling the phenotypic expression of the system.     

Canola genotypes differ in potassium efficiency during vegetative growth

There is no knowledge about the differential capacity of canola genotypes to take up potassium (K) and produce dry matter under conditions of low soil K availability. Hence, 84 canola genotypes were screened for K efficiency in the glasshouse. Plants were grown in sealed pots containing K-responsive, sandy soil without or with K added. Twelve genotypes were selected for advanced screening in the glasshouse in a different K-responsive soil. Genotypes with a mean K efficiency ratio (the ratio of shoot dry weight at deficient and adequate K supply) greater than one standard error above or below the median genotype value were classified as K-efficient or K-inefficient, respectively. There were significant differences between genotypes in the K efficiency ratio in both screening experiments, indicating that genotypes responded differently to K availability. In the initial screening experiment, 19 genotypes were rated as K-efficient and nine genotypes rated as K-inefficient based on the K efficiency ratio. In the advanced screening experiment with 12 genotypes, three genotypes were rated as K-efficient and two as K-inefficient. Genotypes Wesbarker and Rainbow were K-efficient and Genkai K-inefficient in both experiments. Correlation of the K efficiency ratio with (i) shoot K content in the initial and advanced screening and (ii) shoot K concentration in the advanced screening, indicates that the observed differences in K efficiency were due to genotypic differences in both the uptake and the utilization of K. K-efficient genotypes have a potential to improve canola yields on soils with low K availability.