携带dep1基因（直立密穗）的水稻品种具有高产和高氮利用效率的潜力。然而，在田间条件下，对这些品种高产和高氮利用效率有关的农艺和生理性状研究的较少。因此，本研究在0和120 kg N ha^-1下对遗传背景均为南粳6号的两个分别携带DEP1 (NIL-DEP1) 和dep1-1 (NIL-dep1)基因的近等基因系材料（NILs）进行了产量和氮利用效率评价。综合所有的氮肥处理和种植年份，NIL-dep1的产量和氮素籽粒生产效率（NUEg）分别比NIL-DEP1高25.5%和21.9%。NIL-dep1相对于NIL-DEP1的产量优势主要源于较大的库容（即较高的总颖花数）、较高的结实率、总干物质积累和收获指数。氮素利用而非氮素吸收更有利于NIL-dep1的高产。NIL-dep1显著较高的NUEg与其较高的氮和干物质转运效率、较低的成熟期叶片和茎秆氮素浓度以及较高的叶片谷氨酰胺合成酶（GS）活性有关。综上，在大田条件下，dep1通过提高籽粒灌浆期的叶片GS活性增加氮素和干物质转运，进而提高水稻产量和氮利用效率。

双季稻双直播模式是一种省工、节本的轻简化栽培措施，可有效应对当前双季稻种植面积逐年下降的现状。华中地区温光资源有限，双季稻双直播模式必须选用生育期在95天左右的超短生育期品种才能保障安全生产。此外，因直播稻群体密度大、扎根浅，在实际生产中往往面临着倒伏风险高的问题。然而，目前关于超短生育期水稻品种在双季稻双直播模式下的抗倒性表现和抗倒性提高途径尚不明确。因此，本研究旨在揭示华中地区双季稻双直播模式下超短生育期水稻品种的抗倒机理。田间试验于2017-2018年在湖北省武穴市进行，设置高、低两个氮肥水平，选用四个超短生育期水稻品种为供试材料，于齐穗后15天测定倒伏相关性状。结果表明，超短生育期水稻品种在两个氮水平下的生育期和产量的变异范围分别为85-97天和4.59-7.61 t ha^-1。在该产量水平下，弯曲力矩是造成氮肥处理和品种间倒伏指数差异的主要原因，而抗折力及其他茎秆形态指标并未显著影响倒伏指数。弯曲力矩主要受株高的影响，超短生育期水稻品种的株高从95.4 cm降低至80.5 cm，弯曲力矩降低32.0%，倒伏指数降低22.4%，但是产量没有显著降低。因此，在目前的产量水平下，降低超短生育期品种株高是提高双季稻双直播模式抗倒性的有效措施。但是在未来超短生育期品种产量潜力进一步提升的进程中，育种家们更应该关注增强茎秆抗折力，以进一步提高双季稻双直播模式的产量和稳产性。

     Yield and fiber quality of cotton even varies within locules in a boll, but it is not clear how yield components and quality parameters are altered across seed positions of a locule (SPL). A field experiment was arranged in a split plot design with transgenic insect resistant Bt (Bacillus thuringiensis) cotton hybrid cultivar CRI75 and conventional cultivar SCRC28 as the main plots, and three plant densities (15 000, 51 000 and 87 000 plants ha^–1) as the subplots in 2012 and 2013 at Anyang, Henan Province, China. Cotton was hand harvested by node and fruiting position, and then seeds of the first fruiting position bolls from nodes 6–10 were separated by SPL. The effects of plant density on lint yield, fiber quality, especially across SPL were determined. It was showed that plant densities of 51 000 and 87 000 plants ha^–1 increased lint yield by 61.3 and 65.3% in 2012 and 17.8 and 15.5% in 2013 relative to low plant density (15 000 plants ha^–1), however, no significant difference was observed between 51 000 and 87 000 plants ha^–1. The number of bolls (boll density) increased while boll weight decreased as plant density raised, and no significant changes occured in lint percentage in 2013 but increased with plant density in 2012. The number of bolls in upper nodes and distal fruiting positions, the number of seeds per boll, seed area (SA) and seed vigor index increased with decreasing plant density. Seed area was found to be greater from the base to the middle compared to the apex of a locule. Mote frequency (MF) increased as plant density increased, and fiber quality was the best at the middle of the locule regardless of plant density. As the number of fibers per seed area is genetically determined, adjusting plant density to produce more seeds and greater seed area can be a potentially promising alternative to improve lint yield in cotton. These findings might be of great importantance to cotton breeding and filed management.

The sweetpotato whitefly Bemisia tabaci (Homoptera: Aleyrodidae) is a destructive pest of agriculture and horticulture worldwide. Recent phylogenetic analysis using mitochondrial cytochrome oxidase 1 sequences indicates that this whitefly is a species complex including at least 24 morphologically indistinguishable but genetically distinct cryptic species. In this study, the inter-species crosses of Middle East-Asia Minor 1 (MEAM1), Mediterranean (MED) and Asia II 7 cryptic species, which were referred to as B, Q and Cv biotypes before, were conducted in two different devices, leaf cages (7 cm3) and cylinder cages (280 cm3), and at three temperatures of 22, 30 and 38°C. Results indicated that no female progeny were produced in the reciprocal cross between MEAM1×Asia II 7, between MED×Asia II 7 cryptic species neither in leaf cage nor in cylinder cages, while 0.81 and 1.37% of females in the offspring were recorded in the reciprocal cross between MEAM1×MED in leaf cage experiments. Approximately 0.95-0.98% female progeny were recorded in the reciprocal cross between MEAM1×MED at 30°C, 0.77% female progeny were recorded in the single cross direction between MEAM1 × MED at 22°C, and no female progeny were found in their reciprocal cross at 38°C in leaf cage. Our findings indicated that neither space dimension nor temperature have a significant effect on the hybridization of different B. tabaci cryptic species.