Citrus triploid recovery based on 2x x 4x crosses via an optimized embryo rescue approach
Citrus triploid recovery based on 2x x 4x crosses via an optimized embryo rescue approach
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通过优化的胚胎拯救方法，基于 2x x 4x 杂交的柑橘三倍体恢复
DOI：
10.1016/j.scienta.2019.03.038
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发表时间：
2019
影响因子：
4.3
通讯作者：
Guo Wen Wu
中科院分区：
文献类型：
--
作者：
Xie Kai Dong;Yuan Dong Ya;Wang Wei;Xia Qiang Ming;Wu Xiao Meng;Chen Chuan Wu;Chen Chun Li;Grosser Jude W;Guo Wen Wu
无核是柑橘鲜果市场的首要育种目标，三倍体已被证明具有生产无核水果的巨大价值。在本研究中，旨在生产用于开发一些无籽品种的三倍体植物，使用三个优良但有种子的品种作为种子亲本，以及一个新开花的双二倍体和两个异源四倍体体细胞杂种作为花粉亲本，进行了四次 2x × 4x 间倍体杂交。结果，从341个果实中总共获得了1454个发育种子和3409个未发育种子。采用优化的胚胎拯救方法，669粒已发育种子和1301粒未发育种子在体外萌发，以“Nadorcott”橘子和“Bendizao”橘子（多胚）为种子亲本的杂交平均发芽率为52.5%，以“Orah”柑橘（单胚）为种子亲本的杂交平均发芽率为31.0%。然后通过芽和根诱导，共再生出1354株植株，其中401株和54株经流式细胞术（FCM）分析和染色体计数证实为三倍体和四倍体。通过单核苷酸多态性（SNP）标记进一步证实了所选三倍体后代的杂交性质以及所选四倍体后代的两个不同起源（双二倍体和杂交起源）。
Seedlessness is a primary breeding objective for citrus fresh fruit market, and triploids have been proven to have great value to produce seedless fruits. In this study, aiming to produce triploid plants for developing some seedless cultivars, four 2x × 4x interploid crosses were conducted using three elite but seedy cultivars as seed parents and one newly flowered doubled diploid and two allotetraploid somatic hybrids as pollen parents. As a result, a total of 1454 developed and 3409 undeveloped seeds from 341 fruits were obtained. Using an optimized embryo rescue approach, 669 developed and 1301 undeveloped seeds germinated in vitro, with an average germination rate as 52.5% for the crosses using ‘Nadorcott’ tangor and ‘Bendizao’ tangerine (polyembryonic) as seed parents and 31.0% for the crosses using ‘Orah’ mandarin (monoembryonic) as seed parent. Then by shoot and root induction, totally 1354 plantlets were regenerated, among which 401 and 54 plants were proved to be triploids and tetraploids by flow cytometry (FCM) analysis and chromosome counting. Hybrid nature of the selected triploid progenies, as well as two different origins (doubled diploid and hybrid origins) for the selected tetraploid progenies was further confirmed by single nucleotide polymorphism (SNP) markers.