红麻杂交种幼苗生长对盐胁迫的响应

以红麻细胞质雄性不育系P3A、恢复系992及其杂交F1为材料,采用水培法研究盐胁迫对红麻幼苗生长效应以及红麻杂交种对盐胁迫是否存在杂种优势.结果表明:盐胁迫显著抑制红麻幼苗的生长,改变了干物质的分配,使根冠比增大;不同基因型红麻幼苗对盐胁迫的耐性存在显著差异;红麻杂交种的幼苗生长对盐胁迫的响应表现出较强的中亲优势和超高...     

花粉直感效应对桂单0810百粒重的影响

【目的】研究不同玉米品种花粉对桂单0810百粒重的影响,为挖掘该品种的产量潜力奠定基础。【方法】采用完全随机区组设计,利用8个不同玉米杂交种作为父本,对桂单0810进行人工授粉,并对不同杂交种分别进行自交及姊妹交。果穗成熟后,测定自交、姊妹交及杂交果穗的籽粒百粒重。【结果】同一品种自交果穗与姊妹交果穗的百粒重间表现出不同程度的差异,亚航639和太平洋98自交果穗籽粒百粒重比姊妹交极显著降低5.47%和5.36%（P＜0.01,下同）;琛玉969、桂单0810和迪卡008自交百粒重比姊妹交增加0.35%~2.64%,其他各品种自交百粒重比姊妹交降低0.19%~2.11%,且均未达显著水平（P＞0.05,下同）。8个玉米品种的花粉均可增加桂单0810的百粒重,其中正大808、太平洋98、先达901、琛玉969和亚航639等5个品种花粉可极显著增加桂单0810的百粒重。8个玉米品种与桂单0810的杂交组合百粒重均表现出当代（F0）杂种优势（1.31%~12.70%）,7个杂交组合表现出超亲优势。杂种优势最明显的是桂单0810×正大808组合,百粒重比母本桂单0810和父本正大808分别提高12.70%和15.68%,中亲优势达14.17%。【结论】玉米品种桂单0810易接受外来玉米品种花粉,通过花粉直感效应增加自身百粒重并具有当代杂种优势和超亲优势;其花粉直感效应因父本基因型不同而异。     

黑莓F1代杂交优株及其亲本果实营养品质特性分析

为了评价黑莓杂交育种的效果,对初选出的21株F1代杂交黑莓优株及其亲本的果实营养品质进行了分析比较。结果表明:这些杂交优株综合超亲优势平均值为(117.63±97.40)%,超亲遗传效应较好的5株序号依次为7-10-6,4-4-12,6-6-3,7-10-2和6-2-2,可重点作为进一步优质育种资源利用的对象。在21个F1代优株中,5-8-1果实的可溶性固形物含量最高(13.10%),5-8-2果实酸含量最低(0.56%)、固酸比最高(21.25),7-10-6果实酸含量较低、固酸比较高,可作为鲜食品种种质进行培育和利用;6-2-2和2-9-1的果实总酸含量(分别为1.78%和1.39%)和总花色苷(分别为151.09 mg/100g和129.62 mg/100g)含量均较高,固酸比较低(分别为5.91和6.59),可重点作为加工用途品种种质资源加以利用。     

Heterosis in relation to genetic divergence in maize (Zea mays L.)

Summary The magnitude of heterosis was examined in relation to genetic divergence among 10 parents in a 10 × 10 diallel cross of maize. The 10 parents (varieties) were selected on the basis of multivariate analysis of quantitative characters using Mahalanobis' D²-statistic from a lot of 64 varieties of maize belonging to different geograshical regions of the world. The magnitude of heterosis for grain yield and its components was found to be higher with moderate (intermediate) parential diversity than with extreme ones. The results indicated that not only the genetic diversity but the high per se performance with respect to specific characters of interest should be taken into consideration also while selecting parents for hybridization.     

杂交稻及其亲本稻米品质性状与遗传规律研究

以通过审定并大面积推广和新配的18个杂交稻品种及其亲本为研究对象,以优质常规稻湘晚籼13号、湘晚籼17号、星2号和Basmati 370作对照,进行稻米品质中亲优势和超亲优势的遗传分析。结果表明,杂交稻的糙米率和精米率的平均中亲优势和平均超亲优势均表现为正;杂交稻的整精米率的中亲优势和超亲优势均表现为负;杂交稻平均千粒重为26.48 g,介于不育系和恢复系之间,平均中亲优势表现为正,平均超亲优势表现为负;杂交稻的平均粒长、粒宽和长宽比分别为6.59 mm、2.24 mm和2.98 mm,平均中亲优势和平均超亲优势均表现为正;杂交稻平均垩白粒率和垩白度为7.5%和17.86%,平均中亲优势和平均超亲优势均表现为负;杂交稻的直链淀粉含量平均为16.98%,介于不育系和恢复系之间,平均中亲优势表现为正,平均超亲优势表现为负;杂交稻的胶稠度平均为36.28mm,平均中亲优势和平均超亲优势均表现为负。因此,依据上述杂交稻亲本和杂种稻米品质遗传关联,可选择稻米品质适当的父母本来配置并选育具有理想米质的杂交稻组合。     

辣椒杂交一代外观性状遗传表现的观察

通过对2001年和2002年两a对海南冬季辣椒品比试验结果的分析，发现在辣椒的果纵径和果横径遗传中存在超亲临界点，亲本果横径或果纵径的差值小于相应的超临界点时，其后代的果横径或果纵径出现超亲优势。果色、果面特征的遗传规律与前人研究结果一致；果头遗传以大头为显性。     

云南割手密种、斑茅种、滇蔗茅种后代黑穗病抗性研究初报

通过对云南野生甘蔗血缘后代45个材料的黑穗病抗性鉴定,一是了解云南"YN"系列新血缘亲本抗黑穗病性状遗传效应;二是验证"异质复合分离理论"假说指导抗病育种的科学性。结果显示:(1)有27个材料为1级高抗,3个材料为2级抗病,共30个,占67%;而对照种ROC10和桂糖11号分别为6级、7级感病。表明在传统感病种质基础上导入云南野生种质血缘,能够获得野生血缘高抗黑穗病遗传基础,从中选育的"YN"系列优良亲本能够产生高抗黑穗病杂种优势。(2)在27个1级高抗材料中,有11个属于自交系后代,表明"异质复合分离理论"假说的"自交超亲分离"技术,能够有效地选育出高抗黑穗病的超亲遗传变异亲本,其后代抗病性杂种优势突出。     

Heterosis in rice over environments

Summary Ten CMS (A) lines and their maintainers (B) and seven restorers (R) were used to make 70 crosses (A/R) and 70 reciprocals (R/B) following line x tester design. The 140 crosses and 17 parents (10 B + 7 R lines) were evaluated in six environments created by three nitrogen fertility levels (0, 60, 120 kg N/ha) and two seasons wet (WS) and dry (DS). Hybrids (both A/R and R/B) were superior to their parents in yield. Hybrids flowered earlier and were taller than the parents. Substantial heterosis, heterobeltiosis and standard heterosis were observed in different environments. Extent of heterosis was higher in WS (stress environment) than in DS (favorable environment). Twenty four hybrids outyielded the standard check (IR46) significantly. Most of them were derived from crosses with parental lines: IR54752A/B, IR58057A/B, IR46 and IR54. For days to flowering, the overall mean heterosis, heterobeltiosis and standard heterosis were all negative values. Heterosis for plant height did not change the plant type of hybrids from semi-dwarf to tall because the parents possessed same dwarfing gene. With proper choice of parents hybrids possessing higher yield potential, early maturity and semi-dwarf plant type can be developed for the tropics.     

Usefulness of Andigena (Solanum Tuberosum SSP. Andigena) Genotypes as Parents in Breeding Early Bulking Potato Cultivars

Summary Seven Solanum tuberosum ssp. tuberosum and three Solanum tuberosum ssp. andigena accessions were crossed to produce 12 Tuberosum × Tuberosum (T × T) and 9 Tuberosum × Andigena (T × A) progenies. These families were evaluated for five important traits for two successive clonal generations under short day sub-tropical plains. The differences in yield, average tuber weight and tuber number between {T × T }and T × A families in an early (75 days) crop were not significant. Compared to conventional intra-Tuberosum families, T × A families had significantly higher % tuber dry matter and specific gravity. In contrast to intra-Tuberosum crosses, T × A crosses exhibited a positive heterosis for tuber yield. Compared to T × T families, T × A families showed significantly higher heterosis for yield and tuber number. Comparison of T × T and T × A families and parents using canonical analysis led to the identification of superior hybrid families and superior parents. Some T × A progenies were close to breeding goal and thus can be used for selecting high-yielding cultivars. This revealed the usefulness of Andigena genotypes as parents in developing early bulking potato cultivars with broad genetic base for short day sub-tropical plains.     

杉木生长性状配合力分析

报道了杉木６个优树无性系半双列交配设计在两个试验点造林５．５年的试验结果;在遗传控制方式中,杉木生长同时受一般配合力和特殊配合力控制,特殊配合力效应不低于一般配合力效应;树高,胸径和材积３个生长性状家系的广义遗传０．７３１－０．８０１,狭义遗传０．２２８－０．４８１;杂种优良只有少量组合具有正向优势,其中材积杂种优势最高达２６．０６％,亲本配合力效应及组合生长在亲本间,组合间和地点间均存在显著差异