N2-Fixierung und Ertragsstruktur der Weißen Lupine (Lupinus albus L.) im Vergleich zu Vicia faba L. und Glycine max (L.) Merr. auf verschiedenen Standorten

N₂-Fixation and Yield Structure of White Lupin ( Lupinus albus L.) in Comparison to Vicia faba L. and Glycine max (L.) Merr. on Different Sites
In field studies white lupin ( Lupinus albus L., Eldo ) was compared with faba bean ( Vicia faba L., Herz Freya ) in 1986 and soybean ( Glycine max [L.] Merr., Gambit ) in 1988 on five sites respectively. Total N₂-fixation, which was determined by the extended difference method, and yield components were correlated to weather and soil conditions:
1. While faba bean responded to low pH with delayed nodulation, white lupin showed no decrease in N₂-fixation at pH less than 5.5 as far as soil was not calcareous.
2. The white lupin developed its root system most quickly into further soil depths and produced a root dry weight six times as large as that of faba bean in the soil layer 60-90 cm until the end of July (Bayreuth).
3. Despite on the calcareous sites the white lupin showed the highest total-N₂-fixation (max. 36 g N/m²) throughout, the N-gain for the succeeding crop was up to 8 g N/m² for white lupin and faba bean as well. In contrast the N-balance of soybean was mostly negative.
4. Seed yields of white lupin (48-450 g/m²) ranged between those of faba bean (145-549 g/m²) and of soybean (89-290 g/m²); its raw protein yields were the highest found (max. 158 g/m²) though.     

大豆不同生育时期叶绿素含量QTL的定位及其与产量的关联分析

利用来自波高×南农94-156的151个RI家系检测与4个不同生育时期叶绿素含量（累积量、净增量）有关的QTL,并分析其与籽粒产量、表观生物学产量和表观收获指数的关系。结果表明,与叶绿素累积量有关的QTL位于D1a+Q、F、G、H、L和M连锁群上,每个QTL可解释表型变异的6.9%~23.4%。V6和R2期没有检测到2个年份均表达的QTL,而在R4期检测到4个在2个年份均表达的QTL（qccF.1、qccG.2、qccH.1和qccM.1）,R6期仅检测到1个QTL（qccH.1）在2个年份均表达,该QTL在R4也表达。与叶绿素含量净增量有关的QTL位于B2和L连锁群上,在V6-R2时期没有检测到与叶绿素净增量有关的QTL,在B2和L连锁群上的两个QTL（qccB2-1.1和qccL.1）在R2-R4和R4-R6时期均表达,qccB2-1.1可解释表型变异的6.4%~9.8%,而qccL.1所解释表型变异达29.5%~31.3%。但这两个QTL在R2-R4和R4-R6时期表达的性质不同,且与2年均表达的籽粒产量QTL共位。这印证了生育后期叶绿素含量与籽粒产量间存在的极显著正相关。     

水稻、大豆、玉米光合速率的日变化及其对光强响应的滞后效应

用LI-6400光合测定系统对水稻、大豆和玉米3种作物在不同生育时期叶片光合速率的日变化规律进行了研究。结果表明:在各个生育时期,C3作物(水稻、大豆)叶片的光合作用均存在午休现象。而午休现象的产生是气孔因素与非气孔因素共同作用的结果。其中“气孔因素”是高温加剧蒸腾作用,气孔对蒸腾作用的反馈抑制造成的。C3作物(水稻、大豆)叶片的光合速率对光强的响应在上午和下午存在明显差异,上午利用光能的能力明显大于下午。这主要表现在上午的表观初始量子效率比下午大。光合产物对光合作用的反馈抑制会造成这种量子效率的差异性。无论是气孔限制还是光合产物反馈抑制都可能是导致光合速率对光强响应产生“滞后效应”的主要原因。C4作物(玉米)的午休现象不明显,光合速率对光强的响应在上午和下午的差异也不明显,不存在明显的“滞后效应”,这可能与C4作物(玉米)自身的生理特性适应高温的能力有关。     

Uniformity, Performance and Seed Quality of Soybean (Glycine max (L.) Merrill) Seed Crops Grown from Sub-samples of One Seed Lot Obtained after Selection for Physical Seed Attributes

In a glasshouse experiment it was examined whether narrow grading and selection from a commercial soybean seed lot cultivar 'IAS-5', could improve the uniformity of the seed crop grown from it and thereby enhance yield, quality and uniformity of seeds produced. The classes created were: Control (original seed lot); Size-graded seeds (projected area measured by image analysis 37–46 mm²); Non-cracked seeds; Yellow seeds; Size-graded sound seeds (size-graded, non-cracked, yellow, non-wrinkled, non-etched). Compared to the control, percentage of emergence, survival and number of yielding plants were enhanced in crops from non-cracked, yellow or size-graded sound seeds. Differences in plant numbers did not result in differences in crop yield. The different seed lots also did not differ in crop uniformity: time interval between stages of plant development, plant height 20 days after sowing, yield components, physical or physiological quality attributes of seeds produced, and respective coefficients of variation were similar. Fewer plants survived in crops showing a larger variation in plant height 20 days after sowing, thus reducing differences in initial plant-to-plant variation. Creating more uniform crops by additional grading or selection of commercial seed lots may therefore not be promising.     

Genetic analysis for the leaf pubescence density and water status traits in soybean [Glycine max (L.) Merr.]

Leaf pubescence density (PD) is an important component for the adaptation of soybean [ Glycine max (L.) Merr.] to drought-prone environment. Quantitative trait loci (QTL) controlling PD on the upper surface of leaf blade (PDU), PD on the lower surface of leaf blade (PDL), leaf wilting coefficient (WC) and rate of excised leaf drying (ELD) were identified using recombinant inbred lines (RILs) population from the cross between soybean cultivars 'kefeng1' and 'nannong1138-2' at the field soil drought stress stage from the mid-end of stem elongation to onset of flowering. A total of 20 QTLs were detected on molecular linkage groups (MLGs) A2, D1b, E, H, G and I with individual QTL explained 4.49–23.56% of phenotypic variation by composite interval mapping. The QTLs for PD on MLG H were mapped to near Ps locus while the QTLs on MLG D1b were located near Rsc-7 . Three genome regions for PD and water status traits on MLGs A2, D1b and H were associated. This study revealed that leaf surface PD may play an important role in the soybean drought tolerance.     

大豆根区逆境耐性的种质鉴定及其与根系性状的关系

依根系类型从黄淮海和长江中下游地区301份代表性材料中选取62份，以株高、叶龄、地上部干物重、地下部干物重为指标，采用平均隶属函数值方法鉴定了苗期耐旱性、苗期耐铝毒性，加上主茎节数、分枝数、单株荚数、单株粒数、百粒重等性状鉴定了后期耐旱性，并通过钒钼黄比色法测定植株P含量鉴定了苗期耐低磷性。筛选出1级苗期     

Effect of Deep Placement of Slow-release Fertilizer (Lime Nitrogen) Applied at Different Rates on Growth, N2 Fixation and Yield of Soya Bean (Glycine max [L.] Merr.)

A new fertilization method with deep placement of slow‐release N fertilizers, such as coated urea and lime nitrogen (LN) (calcium cyanamide) at 20 cm depth was found to promote soy bean seed yield. In the present study, the effect of deep placement of LN was investigated on different parameters such as growth, N accumulation, N₂ fixation activity and yield of soy bean by applying LN at different rates in the rotated paddy field of Niigata, Japan. In addition to the basal fertilizer, ammonium sulphate (16 kg N ha^?1), deep placement of LN was conducted by applying various amounts such as 50 kg N ha^?1 (A50), 100 kg N ha^?1 (A100) and 200 kg N ha^?1 (A200) at 20 cm depth in separate plots. A ¹⁵N‐labelled LN fertilizer was also employed for each of the above treatments to calculate N utilization from LN in separate plots. Soya bean plant growth and N₂ fixation activity were periodically analysed. Both plant growth and N accumulation were found to increase with LN treatment compared with control plants. An increase in N₂ fixation activity was found in the A100 plots. The total seed yield was the highest in the deep placement of LN with A100 (73 g per plant) compared with other treatments. The visual quality of harvested seeds also showed that A100 enhanced the quality of seeds compared with other treatments. Thus, it is suggested that N fertilization management with particular reference to optimum amount of fertilizers is important for maximum growth, N₂ fixation and enhancement of seed yield of soy bean.