小麦新品种淮麦33适宜播期播量研究

为探明小麦新品种淮麦33的最佳播期和适宜播量,以半冬性小麦新品种淮麦33为研究材料,采取播期、播量两因素互作裂区试验设计,分析播期、播量互作条件下对产量及产量三要素的影响。结果表明,处理组合A2B2、A3B5产量最高,淮麦33适宜播期为10月10日左右,适宜播量为222.0kg/hm2左右。     

豫北地区‘郑麦7698’适宜播期播量的研究

为了筛选适宜的播期、播量,使良种良法配套,充分发挥‘郑麦7698’在豫北地区的丰产性,研究了‘郑麦7698’在不同播期播量下的产量及产量构成。结果表明：随着播期的延迟,小麦成穗数逐渐减少,穗粒数逐渐增加,播期对千粒重的影响未达显著水平,产量随播期的推迟而逐渐降低。播量越大,小麦的成穗数越高,穗粒数越少,播量对千粒重的影响未达到显著水平,而播量最大的处理（225 kg/hm2）产量最高。‘郑麦7698’产量最高的组合为播种期10月10日,播量225 kg/hm2,而播期为10月10日播量为187.5 kg/hm2的组合次之。总之,‘郑麦7698’在豫北地区的适宜播种期范围为10月5日至10日,相应的播量为225 kg/hm2左右。     

氮磷钾配施对花生产量的影响及效应分析研究

为探寻大花生新品种‘青花7号’的最佳施肥方案,采用三因素二次回归通用旋转组合设计方法,建立了氮、磷、钾施肥量与产量关系的效应方程.通过对回归方程的检验及效应分析,探讨了氮、磷、钾肥的单因子效应、互作效应和最佳施肥量.结果表明,施氮、磷、钾肥对花生产量具有明显的增产作用,其肥料效应顺序为钾肥>磷肥>氮肥;氮磷互作对花生产量的影响为极显著.对于试验地块种植的花生新品种‘青花7号’获得高产的最佳施肥组合为:氮肥106.08~133.92 kg/hm2,磷肥159.12~200.88 kg/hm2,钾肥为138.28~161.72 kg/hm2.     

不同栽培措施对高粱产量的影响

为了探讨不同栽培措施对不同高粱品种产量的影响,寻求高粱获得高产的最佳栽培模式,本试验以‘晋杂23号’和‘晋中405’为试验品种,在山西省农业科院经济作物研究所的试验田研究了不同密度、施肥量、播期对高粱试验品种产量的影响。结果表明,‘晋杂23号’属丰产型品种,不宜密植;‘晋中405’属密植类型,以群体产量获得高产;随着播期的推迟,‘晋杂23号’和‘晋中405’的产量都呈下降趋势,且差异显著。最佳栽培措施:‘晋杂23号’为225 kg/hm2施肥水平、12万株/hm2密度水平及5月2日的播期;‘晋中405’为225 kg/hm2施肥水平、15万株/hm2密度水平及5月2日的播期。     

大豆新品种黔豆8号的适宜播种期研究

为探索大豆新品种黔豆8号的适宜播种期,在代表贵州省西南部大豆主产区的盘县对大豆新品种黔豆8号进行了7个不同播期处理试验.结果表明对各播种期对鲜食英产量和干籽粒产量的影响差异达极显著,对生育性状影响显著,对形成产量的主要农艺性状（英／粒等）影响较大.试验结果确定了黔豆8号在盘县作为900kg/667m以上高产鲜食英生产的播期为4月22日-5月2日,提早上市可于4月2日开始播种,明确了黔豆8号作为杆子粒生产达到220kg/667m2以上的播种时期为4月12日-4月22日.     

不同栽培条件对国审稻盐两优2208产量及其产量性状的影响

为探索和挖掘国审稻‘盐两优2208’的栽培措施和高产潜力，本研究采用多因素随机区组试验设计，分析了不同播期、种植密度和施肥量对优质国审稻‘盐两优2208’产量及其产量性状的影响。结果表明：播期、种植密度和施肥量等因素对‘盐两优2208’的产量及其产量性状均有极显著影响；不同播期、种植密度和施肥量对产量及其相关性状的互作效应发现，产量分别在A2B2、A2C2和B2C2互作效应下达到最高，产量相关性状在互作效应影响下，在不同处理间的差异较为复杂，总体来看，千粒重、结实率和有效穗对产量潜力关联较大，在这几个相关性状值在互作效应中最高时，产量潜力往往也最高。在‘盐两优2208’高产栽培时，应适时播种，合理密植，注重灌浆期水肥管理，氮肥施用适当后移，为增加穗粒数并提高结实率，需在齐穗时增施粒肥，为实现高产奠定基础。     

不同栽培条件对国审稻‘盐两优2208’产量及产量性状的影响

为探索国审稻‘盐两优2208’的栽培措施,挖掘其高产潜力,本研究采用多因素随机区组试验设计,分析了不同播期、种植密度和施肥量对优质国审稻‘盐两优2208’产量及其产量性状的影响。结果表明:播期、种植密度和施肥量等因素对‘盐两优2208’的产量及其产量性状均有极显著影响;产量分别在A2B2、A2C2和B2C2互作效应下达到最高,产量相关性状在互作效应影响下,在不同处理间的差异较为复杂。总体来看,千粒重、结实率和有效穗对产量潜力关联较大,这几个相关性状值在互作效应中最高时,产量潜力往往也最高。在‘盐两优2208’高产栽培时,应适时播种,合理密植,注重灌浆期水肥管理,氮肥施用适当后移。为增加穗粒数并提高结实率,需在齐穗时增施粒肥,为实现高产奠定基础。     

不同播期与播量对 ‘九麦 2号’ 小麦产量及品质的影响

摘 要：研究目的：为了探讨冬小麦在关中中部的最佳播期和最佳播量，以陕西省新审定小麦品种‘九麦2号’为材料，研究了在N、P、K配施基础上，不同播期与播量对其产量及品质的影响。方法：本试验采用两因素二次D饱和最优试验设计，设置4个播期水平，4个播量水平，6个处理组合，3次重复，随机排列。结果表明：‘九麦2号’在关中中部产量7500~8250 kg/hm2的适宜播期为10月11日到10月19日，适宜密度在2.17×106株/hm2到2.95×106株/hm2。在播期为10月17日，密度为2.45×106株/hm2时产量可达最高8512.5 kg/hm2。不同播期播量对‘九麦2号’小麦品质也有一定的影响，10月22日播种，密度1.80×106株/hm2处理籽粒品质较好，沉降值达到39.23 mL、蛋白质含量达到14.34%、湿面筋含量达到31.01%、稳定时间为9.35 min，拉伸面积为57.96 cm2。结论：适期适量播种有利于提高‘九麦2号’小麦产量，适期晚播有利于改善其品质，适期晚播和适当加大播种密度有利于兼顾小麦产量水平与品质水平的协调一致。     

绿豆新品种冀绿7号产量影响因素的研究

在绿色标准化生产条件下,研究了播种期、密度和施肥量三因素对绿豆新品种冀绿7号产量和品质的影响.研究结果表明:播种期对冀绿7号夏播绿豆产量的影响最大,其次是密度,最后是施肥量;冀中南地区夏播绿豆产量和品质影响因素的最优组合是6月20日播种、密度1.2万株/667m2、施肥量10kg/667m2.     

限灌条件下环渤海低平原区冬小麦最佳播期播量行距研究

为探索环渤海低平原区冬小麦在限采条件下的最佳播期播量和最佳的空间分布状态,以‘沧麦6005’为试验材料,通过裂区试验设计,以播期为主处理,设5个水平(A1~A5),以播量为副处理,设4个水平(B1~B4),研究了‘沧麦6005’的群体结构、干物质积累、叶面积指数及产量。结果表明:随着播期的推迟,产量、群体数量均呈降低趋势;在较为适宜的播期条件下,随着播量的增大,产量、群体数量出现先增加后降低的趋势;当播期较晚时增加播量可以提高产量;适期播种有利于提高叶面积指数和群体干物质量的积累;适当晚播可以减少无效分蘖和无效叶面积,提高成穗率。不同行距对小麦产量影响显著,行距为20 cm时为最佳。分析认为环渤海低平原区‘沧麦6005’的适宜播期为10月3日到10月13日,适宜密度为375万/hm~2到450万/hm~2基本苗。     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Breeding apomictic bahiagrass (Paspalum notatum Flügge) with improved turf traits

The development of a turf‐type bahiagrass could have a remarkable impact on the billion‐dollar turf industry in the south‐eastern United States. The goals of this study were to (i) select bahiagrass genotypes with improved turf attributes and (ii) determine the reproductive mode and seed fertility of selected genotypes. The population included mutants, wild types, hybrids and standard cultivars evaluated at two locations for two years. Morphological variation was observed and clonal repeatability (H²) ranged from 0.27 to 0.90. Flowering was extremely reduced in some mutants, which also exhibited dark green colour, finer texture and reduced canopy height. Cytoembryological observations revealed that diploids reproduced sexually and tetraploids by obligate or facultative apomixis. Genotypes with superior seed fertility were identified, while others were comparable to the standard cultivars. While mutant plants exhibited great morphological variation, the random mutations did not affect their reproductive mode, validating the use of mutagenesis in apomictic species. The high H² indicated that selection for improved turf attributes could be successfully performed with the advantage of clonal seed propagation.     

Inheritance of fruit colour in a wild Russian red raspberry seedling

Summary A new gene, i, from a self-incompatible wild Russian Rubus idaeus seedling is described. The gene i interacts with the fruit colour gene T, Tii plants having apricot instead of red fruits, and spines, leaves and stems pigmented to varying degrees. A deficit of apricot-fruited seedlings in progenies segregating for i could be explained by linkage between i and the self-incompatibility S locus with a crossover value of approximately 26.7%.Segregations for spine colour in crosses and backcrosses of the Russian seedling with two green-spined (ttII) raspberries selected for their yellow fruit colour, showed that both the latter carried the spine colour intensifier gene P. This suggests that earlier authors were incorrect in attributing the apricot fruit colour developed by some tt plants to a pleiotropic effect of P.     

Flag Leaf Senescence, as Evaluated by Numerical Image Analysis, and its Relationship with Yield under Drought in Durum Wheat

Senescence was evaluated at different stages of the grain‐filling period in eight durum wheat varieties using numerical image analysis (NIA). The varieties were grown under early, severe drought conditions on the high plains of Sétif in Algeria. After flowering, three different irrigation treatments were applied. Treatment effect was small, while a genotypic effect was noted for most of the senescence parameters. Senescence correlated to biomass, while the maximal rate of senescence, V_smax, correlated to thousand‐kernel weight. The potential of the method of numerical image analysis for monitoring flag leaf senescence, detecting genotypic variability and selecting genotypes with delayed senescence is discussed.     

Cowpea (Vigna unguiculata): Genetics,genomics and breeding

Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers.     

Screening for resistance to take-all in wheat,triticale and wheat-triticale hybrid lines

Summary Fifteen triticale and wheat-triticale hybrid lines were evaluated for resistance to the take-all fungus Gaeumannomyces graminis var. tritici and compared with five wheat and two rye lines in inoculated field and pot trials. The triticale and wheat-triticale hybrid lines varied in rye chromosome number and degree of resistance expressed. One line, Venus with seven pairs of rye chromosomes consistently showed levels of resistance intermediate between wheat and rye. A trend was observed where increasing rye chromosome content led to greater resistance but exceptions showed that variation within triticales could not be ascribed to rye chromosome content alone.     

Insect resistance in potatoes: sources,evolutionary relationships,morphological and chemical defenses,and ecogeographical associations

Summary The past 25 years, 1686 potato accessions, representing 100 species in the genus Solanum L., subgenus Potatoe, section Petota, were evaluated for field resistance to one or more of the following insect pests: green peach aphid, Myzus persicae (Sulzer); potato aphid, Macrosiphum euphorbiae (Thomas); Colorado potato beetle, Leptinotarsa decemlineata (Say); potato flea beetle, Epitrix cucumeris (Harris); and potato leafhopper, Empoasca fabae (Harris). Accessions highly resistant to green peach aphid were identified within 36 species, to potato aphid within 24 species, to Colorado potato beetle within 10 species, to potato flea beetle within 25 species, and to potato leafhopper within 39 species. Resistance levels were characteristic within Solanum species. Insect resistance appears to be a primitive trait in wild potatoes. Susceptibility was most common in the primitive and cultivated Tuberosa. Insect resistance was also characteristic of the most advanced species. The glycoalkaloid tomatine was associated with field resistance to Colorado potato beetle and potato leafhopper. Other glycoalkaloids were not associated with field resistance at the species level. Dense hairs were associated with resistance to green peach aphid, potato flea beetle, and potato leafhopper. Glandular trichomes were associated with field resistance to Colorado potato beetle, potato flea beetle, and potato leafhopper. Significant correlations between insect score and altitude of original collection were observed in six of thirteen species. Species from hot and arid areas were associated with resistance to Colorado potato beetle, potato flea beetle, and potato leafhopper. Species from cool or moist areas tended to be resistant to potato aphid.Abbreviations EBN Endosperm Balance Number     

A self-fertile trigeneric hybrid in the Triticeae involving Triticum,Hordeum, and Secale

Summary A self-fertile trigeneric hybrid in the Triticeae involving species from the Hordeum, Triticum and Secale genera has been produced. The trigeneric hybrid was obtained by crossing octoploid triticale (x Triticosecale Wittmack) with octoploid tritordeum (H. chilense × T. aestivum amphiploid). The trigeneric hybrid presented a genome constitution AABBDDRH^ch and 2n=8X=56 chromosomes. The cytogenetical analyses showed no chromosome instability nor homeologous pairing between Hordeum and Secale chromosomes. In the F₂ generation the chromosome number ranged from 42 to 52. Within this range, the plants with smaller numbers of chromosomes were more frequent. A preferential transmission of rye chromosomes could be inferred.     

Evolving gene pools in crop plants

Summary The three gene pool system can be applied usefully to the whole range of crop plants. The primary gene pool (GP1) show varying degrees of fragmentation. No morphological discontinuity is apparent between wild and cultivated Lathyrus sativus but clear discontinuities have developed between conspecific wild and cultivated Phaseolus and Vigna species. Further discontinuities can develop in cultigens where disruptive selection has been practiced, as in Beta vulgaris, Linum usitatissimum and Brassica oleracea where more than one distinct crop has evolved within a single biological species. Each such crop has developed its own distinctive gene pool.