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.     

Identification of the Chromosomes in the 'Esto' Set of Rye Trisomics

The original identification of the chromosomes involved in each of the lines of the act of primary trisomics of winter rye variety ‘Esto’ does not correspond with recent results of gene localization studies. Using known morphological marker genes, N-banding and test crossing with the standard translocation tester set, a more precise identification was possible. In the nomenclature of the Triticinae, the lines can be designated as follows: A = 7R; B = 5R; C = 2R; D = 3R; E = 4R; F = 6R; G = 1R.     

Cytogenetical studies on African rice,Oryza glaberrima Steud. 3. Primary trisomics produced by pollinating autotriploid with diploid

Summary In order to promote cytogenetical studies on Oryza glaberrima (2n=2x=24), I produced primary trisomics in the progeny of the autotriploid. When the autotriploid was pollinated with the diploid, 136F1 seeds (5.8% of the number of spikelets pollinated) were obtained. The numbers of chromosomes of 31 surviving progeny varied from 24 to 28, with plants having 2n=25 occurring at the highest frequency (34.4%). The primary trisomics differed from one another as well as from the normal disomics in many aspects. The differences were attributed to a single extra chromosome in each trisomic type. Nine primary trisomics were classified into 8 types on the basis of morphological and reproductive features. Seeds were obtained from all primary trisomics except for Type D by self pollination, open pollination or pollination with the disomics. I was able to maintain 7 types of primary trisomics by seed propagation. The primary trisomics which are capable of expressing subtle genetic dissimilarities should be useful for studying the relationship between the two cultivated species of rice at the level of individual chromosomes.     

Genetic segregation of the deformed flower gene in trisomics of Solanum chacoense

Summary The gene df (deformed flower), which is expressed as short anther in sensitive cytoplasm, has been incorporated into the trisomic series of S. chacoense Bitt. The cytoplasmic sensitivity and genotypes for the gene df were tested in the original trisomics and their parents. Two diploid parents were found to be homozygous dominant for Df, while one was homozygous recessive. All the parents and trisomics tested had resistant cytoplasm. Six trisomics were heterozygous for df, segregating with a 1:1 ratio when they were crossed to the homozygous testers ([df ^s]dfdf). When the F₁ trisomics (trisomics x [Df ^r]dfdf) were crossed to the homozygous testers, nine of the 13 trisomics segregated with a 1:1 ratio, three with a 0:1 ratio (all deformed) and one trisomic (V1682.3) with a 2:1 ratio. All the parents of the trisomic V1682.3 were homozygous dominant for Df. This clone is believed to be trisomic for the gene df.Cooperative investigation of the Agricultural Research Service, U.S. Department of Agriculture and the Wisconsin Experiment Station, Madison.     

平衡施肥对生菜产量和品质的影响

试验以酸性菜园土为供试材料,通过小区试验研究了平衡施肥对生菜产量、养分形态和品质的影响。结果表明,在供试土壤上平衡施肥明显提高生菜产量,各处理间达到极显著差异(F=19.68>F0.01=5.65),增幅范围为12.1%～27.6%,增产序列为NP2K1>NP1K2Mg>NP1K2PP>NP2K2>NP1K2MgZnB>NP1K2>NP1K2RM,在低钾时增磷、高钾时增镁可提高生菜产量。与CK相比,NP1K2MgZnB处理的维生素C含量降低7.9%,其余各处理维生素C含量提高5.6%～8.3%。NP2K2和NP1K2Mg处理对生菜氨基酸含量影响较大,较CK增加15.8%和17.5%,其余各处理的影响不明显。各处理对生菜硝酸盐含量的影响不一致,NP1K2处理提高了17.0%,P1K2RM处理为显著降低了12.5%。各处理中以NP1K2RM对生菜产量及品质的效果最佳,均有提高。生菜各营养元素形态分别以蛋白氮、非蛋白磷和非蛋白钾为主。NP1K2处理明显提高蛋白态的氮磷钾含量。     

平衡施肥对设施基质栽培番茄生长、品质、矿质元素含量与产量的影响

为明确平衡施肥对设施基质栽培番茄的影响,以番茄(Solanum lycopersicum L.)184品种为试材,按照氮(N)、磷(P)、钾(K)平衡施肥原理设计4个处理,分别为不施肥(CK0)、常规施肥(CK,每667 m²施N肥23.7 kg、P₂O₅ 38.4 kg、K₂O 72.9 kg)、平衡施肥1(T1,每667 m²施N肥38.38 kg、P₂O₅ 16.45 kg、K₂O 53.18 kg)、平衡施肥2(T2,施肥量较T1减少10%,每667 m²施N肥33.58 kg、P₂O₅ 14.4 kg、K₂O 46.5 kg),研究平衡施肥对番茄生长、品质、产量与矿质元素含量的影响。结果表明,平衡施肥可不同程度促进番茄生长,改善品质,提高矿质元素含量和产量,平衡施肥1(T1)效果最优。与常规施肥(CK)相比,T1处理番茄的株高、叶片数、最大净光合速率和根系活力分别提高9.97%、5.19%、25.13%和95.79%;果实可溶性固形物、可溶性糖、铁、镁、钙元素含量与产量分别提高19.82%、16.09%、15.24%、11.30%、69.06%和15.25%。相关性和主成分分析结果表明,番茄品质和产量等指标之间存在一定的相关性与依存关系。根据综合得分模型发现,T1处理的得分最高,CK0最低,说明平衡施肥对设施基质栽培番茄生长、品质、矿质元素含量和产量影响较大,其中,单果鲜重和维生素C(V_C)、磷、钾、铁、锰、锌含量是影响番茄生长和品质的主要因素。因此,平衡施肥1(T1)处理可通过增强番茄叶片光合能力,提高产量和改善果实品质,成为肥料资源合理配置的施肥模式。     

糖甜菜异附加三体的获得及减数分裂行为观察

通过甜菜属近缘种3种间杂交(B.patula×B.cicla F_1,对B.vulgaris杂交),从后代中分离出了3个具有B.patula染色体的异附加三体植株。其中PT5-1植株具有B.patula的红色叶脉性状,且附加染色体明显小于糖甜菜染色体,认定为B.patula的9号染色体,另两株附加的B.patula染色体号未确定。减数分裂终变期1Ⅲ 8Ⅱ频率平均为5.65％,9Ⅱ 1Ⅰ频率为92.50％,都与糖甜菜初级三体有显著差异。中期Ⅰ,1Ⅲ 8Ⅱ频率有所降低。正常四分体频率为93.28％。实际传递率较低。文章还讨论了异附加三体的利用价值。     

科学应对农业干旱

干旱是一个全球性问题.随着全球气候变暖和人类活动加剧,干旱有明显加重趋势.为应对我国面临的农业干旱需正确认识和把握几个关系问题.(1)南北区域之间的关系:从水资源合理利用与粮食均衡增产角度看,目前"北粮南调"的做法不尽合理,应加强南方地区农田水利工程建设,并做出有利干增强南方粮食生产能力的政策调整;(2)高、中、低产田...     

氮磷钾均衡管理对戈壁滩日光温室基质栽培秋冬茬番茄产量与养分吸收的影响

采用日光温室小区试验,研究了氮磷钾均衡管理对戈壁滩日光温室基质栽培秋冬茬番茄产量与养分吸收的影响,以期为戈壁滩日光温室基质栽培蔬菜提供科学施肥依据。结果表明,(1)日光温室秋冬茬番茄栽培基质营养主要限制因子是氮和钾,施磷也有一定增产效果,施氮、施钾和施磷平均分别增产31.2%、17.0%和4.1%。(2)氮磷钾均衡管理处理较习惯施肥能显著增加产量和经济效益,平均增产16.3%,增收17.5%;氮磷钾均衡管理处理产量和经济效益均略高于高氮和高钾处理,产量平均分别增加4.8%和3.0%,经济效益平均分别增加4.9%和3.2%。(3)氮磷钾均衡管理能维持番茄对氮磷钾的吸收量,提高化肥氮磷钾利用率,氮磷钾均衡管理处理的化肥氮、磷和钾利用率分别为25.8%、17.6%和35.7%,而习惯施肥处理的化肥氮、磷和钾的利用率分别为15.9%、6.5%和19.7%。(4)本试验条件下日光温室基质栽培秋冬茬番茄适宜N、P2O5和K2O用量分别为392、136和455 g/m3基质,生产1 000 kg番茄产品对N、P2O5和K2O的推荐量分别为3.1、1.1和3.6 kg。