Seed Storability in Rice: Physiological Foundations, Molecular Mechanisms, and Applications in Breeding

Long-term storage of crop seeds is critical for the conservation of germplasm resources, ensuring food supply, and supporting sustainable production. Rice, as a major food staple, has a substantial stock for consumption and production worldwide. However, its food value and seed viability tend to decline during storage. Understanding the physiological responses and molecular mechanisms of aging tolerance forms the basis for enhancing seed storability in rice. This review outlines the latest progress in influential factors, evaluation methods, and identification indices of seed storability. It also discusses the physiological consequences, molecular mechanisms, and strategies for breeding aging-tolerant rice in detail. Finally, it highlights challenges in seed storability research that require future attention. This review offers a theoretical foundation and research direction for uncovering the mechanisms behind seed storability and breeding aging-tolerant rice.

Effects of Controlled Atmospheres with High_O_2 or High_CO_2 Concentrations on Postharvest Physiology and Storability of "Napoleon" Sweet Cherry

Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively.

Identification of QTLs for seed storability in rice under natural aging conditions using two RILs with the same parent Shennong 265

Seed storability （SS） is an important trait for agronomic production and germplasm preservation in rice （Oryza sativa L.）. Quantitative trait locus （QTL） for seed storability in three storage periods was identified using two sets of recombinant inbred lines （RILs） derived from the crosses with a colnmon female parent Shennong 265 （SN265）. Ten QTLs for seed storability were detected on chromosomes 1, 2, 3, 4, 6, 8, and 12in SL-RILs （SN265/Lijiangxingtuanheigui （LTH））, and a total of 12 QTLs were identified on chromosomes 2, 3, 4, 6, 9, and 10 in SH-RILs （SN265/Luhui 99 （LH99））in different storage periods. Among these QTLs, five major QTLs were identified in more than one storage period. The qSS3-1, qSS3-2, qSS12-1, and qSS12-2 were detected in SL-RILs. Similarly, qSS2-2, qSS2-3, qSS6-2, qSS6-3, qSS6-4, qSS9-1, and qSS9-2 were detected in SH-RILs. In addition, the maximum phenotypic variation was derived from the qSS6-1 and qSS9-2, explaining 53.58 and 29.09%, respectively, while qSS6-1 was a new stable QTL for seed storability. These results provide an opportunity for pyramiding and map-based cloning major QTLs for seed storability in rice.

The Storability and Its Regulatory Mechanism of HuanghuaPear(Pyrus pyrifolia Nakai.)Fruit as Influencedby Postharvest Treatments

Different temperatures and PEF packing treatments were carried out on postharvest Huanghua pear fruit to investigate their effects on fruit storability and the regulatory mechanism. LOX activity, O2- content, AOS activity, ACC synthase activity, ACC content, ACC oxidase activity and ethylene production changed with peaks in the ripening fruit at 20℃ and were inhibited by cold storage, incidence of fruit woolness and fruit decay were lightened as well. Low temperature combined with PEF packing (PEF1 and PEF2) treatments could further improve the fruit storability, maintain preferable quality. There was no significant difference between PEF1 and PEF2 both during cold storage at 1℃ and shelf life at 20℃. The recommended storage period of Huanghua fruit was two months at It and could be extended one month longer with PEF packing treatments.

The Status and Strategy on the Relationship Between Lipoxygenase-3 in Rice(Oryza sativa L.) Embryos and Storability

The degradation of lipids was mainly responsible for the reduction of rice quality and production of stale flavor during its storage. It was proved that LOX-3, the major component of the isozymes accounting for 80% - 90% of total activity, was the key enzyme in above process. Further results indicated that the lack of LOX-3 in Daw Dam led to decrease of lipid peroxidation, alleviating the accumulation of stale flavor during storage, which is caused by hexanal, pentanal and pentanol compounds etc. Genetic survey displayed that the absence of LOX-3 was controlled by a single Mendelian recessive gene. On the other hand, three cloned LOX genes and deduced LOX genes encoding some purified LOXs could not be contributed to the embryo LOX genes by comparing biochemical characterizations of these expressed products and some purified LOXs with known LOXs in rice embryos. The future research should focus on the further influences of LOX-3-null on rice storability. Meanwhile, single-base-trans version in coding region, insertion, deletion and replacement in promoter of LOX genes were related with lipoxygenase-null genotype of soybean and pea. Therefore, the cloning of the recessive gene controlling the null of LOX-3 and its corresponding dominant gene in rice seed embryos will contribute to the understanding of the null molecular mechanism, elucidating the differences of LOX genes expression and regulation in rice embryos. In the last, the breeding strategy of new storable rice, including the theoretical and practical concepts, was surveyed.

Seed Storability of CIMMYT Core Wheat Germplasm Panel and Their Haplotypes in <i>Lipoxygenase</i>Locus

Seed storability (SS), also called seed longevity, is a valuable trait for seed banks and providing reliable crop seeds to farmers, which is usually negatively correlated to lipoxygenase (LOX) activity. In this study, the seed storability of 60 accessions of CIMMYT core wheat germplasm panel (CIMCOG) was investigated through artificial aging (AA) test, including three parameters relative germination potential (RGP), relative germination rate (RGR) and relative seedling vigor index (RVI). Significant positive relationships were observed among RGP, RGR and RVI. And the genotypes at three LOX activity related QTLs/genes QLpx.caas-4B, QLpx.caas-1AL and TaLOX-B1 were also identified with published trait-associated molecular markers. For QLpx.caas-4B, a total of five alleles were detected at the locus of Xgwm251, and one marker-trait association was identified for RVI. Four and two alleles were detected at the loci of QLpx.caas-1AL and TaLoxB1 that were significantly associated with RGP, RGR and RVI, respectively. A total of 9 haplotypes were detected at three lipoxygenase activity related gene loci, and the haplotype of three lipoxygenase loci showed a significant association with RGP, RGR and RVI. The haplotype of Xgwm251-125bp + Xwmc312-247bp + TaLox-B1b produced seeds with the best storability in the CIMCOG, which could benefit the breeding for wheat with good seed storability.

光伏型红外焦平面探测器NETD的理论计算和测试分析

噪声等效温差(NETD)是表征红外焦平面探测器灵敏度的重要参数,除了器件本身的因素以外,与实际应用条件及测试条件密切相关。从红外焦平面探测器NETD的测试方法和流程出发,对光伏型红外焦平面探测器NETD的理论计算公式进行了推导,分析了影响器件NETD的主要因素,对典型红外焦平面探测器在不同积分时间、不同电荷存储量、不同F数及半阱输出条件下的背景限NETD进行了理论计算及分析。在固定背景温度下,通过理论公式可从某一温差的NETD推算出不同温差的NETD,选择典型器件进行验证,从常规NETD测试结果推算出的一组NETD与相应温差下的实测结果符合较好,其中1 K温差的NETD推算结果已非常接近实际情况,可为热像仪系统应用提供参考。

不同中间砧对富士苹果贮藏期表皮蜡质和角质的影响

【目的】对果实表皮的蜡质和角质层组分进行定性和定量测定,探究果实表皮蜡质和角质对果实采后贮藏的影响,以提高果实贮藏品质。【方法】比较SH6和M26作中间砧的富士苹果在常温贮藏期间的失重率和呼吸强度,通过扫描电子显微镜观察表皮蜡质形态和结构的差异,并采用气相色谱/质谱联用仪测定蜡质和角质的单体含量。【结果】常温贮藏期间,SH6果实的失重率和呼吸强度显著低于M26果实,表皮蜡质层厚度、蜡质和角质总量显著高于M26果实。两种砧木果实的果皮中鉴定出28种角质共有成分,34种蜡质共有成分,其中角质共有成分包括14种脂肪酸、7种羟基脂肪酸、2种二羧酸和5种醇。此外,SH6果实还有5种特有角质成分,包括花生四烯酸、顺式-8,11,14-二十烷三烯酸、18-羟基-9,12-十八碳二烯酸、22-羟基二十二烷酸和二十四烷醇。M26果实也有4种特有角质成分,包括十八烷酸、(3β)-3-三羟基-齐墩果-12-烯-28-酸、10,13-二十碳二烯酸和7,10,13-二十碳三烯酸。两种砧木果实的果皮中蜡质共有成分包括5种烷烃、6种醇、4种脂肪酸、12种酯类、2种醛类和4种其他物质。SH6果实还有3种特有蜡质成分,包括熊果醛、二十烷酸丁酯和熊果酸甲酯。M26果实也有3种特有蜡质成分,包括二十烷酸、棕榈酸-3-甲基丁酯和山嵛酸乙酯。相关性分析表明,果实贮藏期间的失重率和呼吸强度与蜡质层厚度呈显著负相关(r=-0.85,r=-0.77),失重率与羟基脂肪酸和酯类含量呈显著正相关(r=0.81,r=0.87),呼吸强度与羟基脂肪酸和二羧酸含量呈正相关(r=0.59,r=0.50)。【结论】与M26作中间砧相比,SH6作中间砧的富士苹果果实具有较厚的表皮蜡质层和更丰富的角质和蜡质含量,使其在贮藏期间具有更低的失重率和呼吸速率。

不同贮藏条件下薄皮甜瓜采后品质特性比较

为探明不同贮藏条件下甜瓜果实采后品质的变化规律,以5个不同的甜瓜品种(‘通甜蜜1号’、‘日本甜宝’、‘通翠1号’、‘通翠3号’和‘羊角蜜’)为试验材料,根据各品种果实生长发育期的单果重变化确定果实的适宜采摘期,并将适宜采摘期的甜瓜果实采收后分别于4、10、15℃条件下贮藏,通过分析各处理的甜瓜果实含水量、失重率、果皮颜色、可溶性固形物含量、果肉硬度等指标的变化,研究不同贮藏时间和温度对果实品质特性的影响。结果表明,‘通甜蜜1号’、‘通翠3号’和‘日本甜宝’的果实采后的失重率、可溶性固形物、硬度和色泽等指标维持较好,耐贮性更佳。贮藏温度4℃条件下果实在贮藏的中后期出现轻微冻害,15℃条件下果实的货架期最短,而10℃条件下果实品质下降速率最慢,可有效维持甜瓜的果实品质,延长果实贮藏期。

不同成熟度木奶果果实品质及耐贮性

以木奶果果实为试材,研究了不同成熟度对果实品质及耐贮性的影响,为确定最佳采收成熟度提供理论依据。结果表明,随着成熟度的提高,果皮颜色由浅红色转粉色至黄粉色,纵径、横径、单果质量、可食率、可溶性固形物含量和固酸比分别上升了7.67%、6.83%、20.05%、8.09%、13.23%和18.51%;色泽指数、硬度和总酚含量分别下降了76.84%、5.94%和18.97%;可滴定酸含量、维生素C含量和总黄酮含量先上升后下降,均在成熟度II时最高,分别为1.39%、3.93 mg/100 g和3.48 mg/g;果形指数和果皮相对电导率较稳定。随着贮藏时间的延长,成熟度III的木奶果果实能够保持较高的硬度、可溶性固形物含量、可滴定酸含量、固酸比、维生素C含量和总酚含量,失重率和果皮相对电导率较稳定。主成分分析及果实品质指数分析表明,成熟度III的木奶果果实品质综合得分最高,且在贮藏过程中综合品质最佳。综上,木奶果果实采收标准为成熟度II~III(花后91~98 d),成熟度III(花后98 d)的果实鲜食品质佳及耐贮性高。

不同品种燕麦种子活力鉴定与耐贮藏性评价

为探究不同品种燕麦种子活力与耐贮藏性差异,筛选具有高活力且耐贮藏的优异种质,本研究以8个品种燕麦种子为试验材料,采用45℃、100%相对湿度人工老化法模拟种子贮藏,通过测定老化0 d(即未老化,对照CK)、老化4 d两种条件下11个种子萌发与幼苗生长特性相关指标变化,运用耐老化系数、综合耐老化系数、主成分分析、隶属函数、综合评价值(D值)和系统聚类分析方法对供试种子耐贮藏性进行综合评价,以期为燕麦高活力强耐贮藏性种质筛选与新品种培育提供理论参考。结果表明:人工老化条件下,除平均发芽时间呈延长趋势外,发芽势、发芽率、发芽指数、种子活力指数、成苗率和幼苗活力指数在所有供试燕麦品种中均呈下降趋势。通过主成分分析,可将11个单项测定指标转换为3个相互独立的综合指标。根据耐贮藏性综合评价D值和系统聚类分析,将8个品种燕麦种子耐贮藏性划分为4个类型,即强耐贮藏性、中耐贮藏性、弱耐贮藏性和极弱耐贮藏性,并筛选出强耐贮藏性品种为“贝勒Ⅱ”、极弱耐贮藏性品种为“海威”,为燕麦高活力强耐贮藏性种质筛选、关键候选基因挖掘及新种质创制与利用提供了理论依据。

紫花苜蓿种子耐贮藏性综合评价及关键指标筛选

为探讨紫花苜蓿(Medicago sativa L.)种子耐贮藏性综合评价方法与关键指标,本研究以36个品种紫花苜蓿种子为材料,采用高温高湿人工老化法模拟种子贮藏,测定了老化0 h(对照组)和60 h(处理组)的发芽势、发芽率、苗长、根长等10个种子萌发与幼苗生长指标变化。采用综合耐贮藏系数、主成分分析、隶属函数分析、系统聚类分析等方法进行综合评价,建立逐步回归分析数学模型。结果表明,种子萌发与幼苗生长指标均呈下降趋势,但对老化处理表现出不同程度响应差异。系统聚类分析将紫花苜蓿种子耐贮藏性划分为强、中、弱和极弱4个等级,其中,‘三得利’和‘公农1号’种子分别属于强耐贮藏性和极弱耐贮藏性等级。根据逐步回归分析模型,发芽势和苗长可作为种子耐贮藏性评价的关键指标。本研究为紫花苜蓿强耐贮藏性种质筛选、关键候选基因挖掘及功能研究奠定理论基础,也为强耐贮藏性新种质创制与利用提供优异亲本材料。

采前肉桂酸处理对‘巨峰’葡萄耐贮性的影响

‘巨峰’葡萄在采后流通和贮藏期间易发生落粒、烂果等情况,造成果实品质下降及严重的经济损失,因此有效控制葡萄果实贮藏期间品质劣变,提高采后保鲜效果具有重要意义。试验设置采前10 d用不同浓度的肉桂酸溶液喷施果穗,无处理为对照(CK),研究采前肉桂酸处理对4 ℃条件下贮藏14 d之内‘巨峰’葡萄果实质构特性、落粒率、腐烂率、果梗褐化度、表面菌群等的影响。结果发现,10 mmol·L^(-1)肉桂酸处理效果最显著,其中果实质构指标、果梗褐化度、果柄脱落指标、落粒率和腐烂率与CK相比均较优。本研究中,在相同贮藏时间内,各处理果实的质构特性指标和果柄脱落指标随肉桂酸浓度增加呈上升趋势,落粒率、果梗褐化度、腐烂率和果皮带菌率随肉桂酸浓度增加而降低;而随着贮藏时间延长,肉桂酸处理对这些指标的影响逐渐减弱。试验表明,采前肉桂酸处理可以有效提高‘巨峰’葡萄的耐贮性。

小果型西瓜耐贮性研究

通过分析北京地区主要种植小果型红瓤西瓜‘L600’与‘京颖’单瓜重、果皮厚度、硬度、中心和边部可溶性固形物含量、维生素C含量随贮藏时间延长的变化,研究不同品种适宜的贮藏期。结果表明,室温26℃储存,果实口感硬脆的西瓜品种‘L600’较果实口感酥脆的西瓜品种‘京颖’耐贮藏时间可长15 d左右,达到30d;贮藏至45d,‘L600’果实可溶性固形物含量下降更多,但含量较‘京颖’高;整个贮藏期间,‘L600’平均维生素C含量与果皮硬度高于‘京颖’。

百蜜系列南瓜品种(系)采后品质变化和耐贮性比较

以百蜜系列南瓜品种(系)为试验材料,在16~18℃下架式贮藏,设置10、20、30、40、50、60 d共6个贮藏时间,测定果实可溶性固形物含量、淀粉含量、可溶性糖含量、β-胡萝卜素含量、维生素C含量、丙二醛含量、呼吸速率、失重率和果皮硬度等营养品质及生理指标,对百蜜系列南瓜品种(系)果实采后的耐贮性和品质变化进行分析,并结合主成分分析、相关性分析、聚类分析进行耐贮性综合评价,以期筛选出耐贮性强的南瓜品种(系)。结果表明,在不同贮藏期,百蜜5号淀粉含量最高,均值为1.39 mg/g;百蜜3号呼吸速率、可溶性固形物含量和β-胡萝卜素含量最高,均值分别为34.60 mg(/kg·h)、10.80%和25.20μg/g;百蜜10号果皮硬度最高,均值为25.17 N;百蜜2号失重率最高,均值为8.95%。主成分分析结果表明,供试南瓜品种(系)的贮藏指标可以用5个主成分来表示,方差累计贡献率达91.922%。进一步采用隶属函数法和聚类分析对百蜜系列南瓜品种(系)进行耐贮性综合评价,结果表明,百蜜10号可作为耐贮藏品种进行推广种植,百蜜2号的耐贮性较差,适合短途运输或就地销售。

采收期对烟富3号苹果果实品质的影响

以15年生烟富3号苹果为试材,研究了甘肃省陇东旱塬区6个采收期(2022年10月5日、10月11日、10月17日、10月23日、10月29日、11月5日)果实低温贮藏时品质生理变化规律及特性。结果表明:随着采收期的推迟,果形指数无显著变化,果实纵径、横径、可溶性固形物含量、可溶性糖含量及固酸比、糖酸比、糖心率均显著增加,硬度及可滴定酸含量、总酚含量显著降低,10月23日采收的果实单果重最大、着色最好、维生素C含量最高,可溶性固形物含量达15.13%。低温贮藏期间,不同采收期果实硬度及可滴定酸含量、维生素C含量均不断下降,可溶性固形物含量先升高后下降,总酚含量先下降后升高,果实呼吸强度、乙烯释放速率均在贮藏120 d时出现峰值;10月17日采收的果实硬度及可滴定酸含量、维生素C含量下降幅度较小,果面光洁度保持稳定,贮藏180 d后,果实硬度、可溶性固形物含量、维生素C含量、L^(*)值均最高,果实呼吸强度、乙烯释放速率峰值、失重率、腐烂率均最低。综合分析,10月23日可作为甘肃省陇东旱塬区烟富3号果实鲜食的最适宜采收期,10月17日可作为长期低温贮藏的最佳采收期。

不同气体成分对甜樱桃果实采后生理及品质的影响

研究了甜樱桃（Prunus avium L.）品种“红灯”在气调（CA,controlled atmosphere）、自发气调（MA,modified atmosphere）和普通冷藏（CK）条件下果实的生理变化、褐变指数、风味品质和耐藏性。结果表明,与CK相比,CA和MA贮藏均能有效地减少果实腐烂和褐变,保持果实硬度和颜色,降低果肉中乙烯和乙醇含量,抑制多酚氧化酶和过氧化物酶的活性,减慢丙二醛含量上升的速率。但是,甜樱桃果实在CA条件下的贮藏效果明显地好于MA,贮藏时间是MA的1.5～2倍。在CA贮藏中又以高CO2浓度处理组合的效果更佳。

磷、钾营养对柑桔果实产量、品质和贮藏性的影响

采用田间试验以柑为材料研究了连续4年施用磷、钾肥后对柑桔果实的产量、品质和贮藏性的影响。结果表明,施用磷、钾肥,尤其磷、钾肥配施可显著提高柑桔果实的单果重和产量,以及采收时果实的可溶性固形物含量、可溶性糖含量、还原糖含量、糖/酸比和维生素C(Vc)含量,降低可滴定酸含量;并且可以有效地降低柑桔果实在贮藏过程中的失重率和烂果率,减缓糖分、酸度和Vc含量的下降。磷钾营养对于提高柑桔果实的耐贮性和维持贮藏过程中果实的风味和营养品质有一定的作用。

福建省5个主栽品种枇杷果实品质比较及其与果实耐贮运的关系

对福建省5个主栽品种枇杷果实的品质进行分析比较,并探讨其与果实耐贮运的关系。结果表明:耐贮运的枇杷果实含水量低、原果胶含量和总酸度高、果实硬度大;总糖和VC的含量高低与枇杷果实耐贮性没有直接关系。可溶性固形物、木质素和纤维素是主要影响枇杷的食用品质,糖酸比和固酸比主要是作为衡量枇杷果实品质的指标。

氮、钾营养对香蕉生长的影响

研究了氮、钾不同供应水平对香蕉产量、品质、贮藏性和抗冻能力的影响。结果表明,以适量配施氮钾肥的N_2PK_2处理香蕉果实农艺性状最佳,品质最优,产量最高,较不施肥处理增产16.1%;且果实贮藏性好,吸芽受冻死亡率最低。在广州市番禺区香蕉产区,获得第一年蕉45 t/hm^2左右的高产,需要施N 667～709、P_2O_5 200～213、K_2O 748～851 kg/hm^2;保持氮钾肥施用比例N:K_2O为1:1.12～1.20为宜。