Seabuckthorn breeding

Seabuckthorn breeding on eco-economic improvement purpose

—Superior plant selection in F1 generation

of ssp mongolica and ssp. sinensis

Jin Zhengpin  Wen Xiufeg  Lun Shunguang  Jin Shuyuan

China Administration Center for Seabuckthorn Development (CACSD)

wenxf@icrts.org

It has been well know that the genes’ newly combination will result much variation within the filial generation, so the fine plant selection standards has been established based on the study of genetic character variation in F1 generation population which got by hybridization between ssp. mongolica and ssp. sinensis. 3 fine plant has been selected from 1500 female plants of filial generation population. 3 of them are with both parents advantages: like as growing is much better than parents and local sinensis; without any irrigation, the fruit size and fruit productivity of plant is much higher than average value of filial population, female parent and local sinensis, the selection intensity of fruit productivity is 3; the thorns are significantly less than selected population and siensis; the fruit with higher quality, especial oil and Ve content. But under water intimidate, the fruit productivity will be influenced, so forth more trails on resistance to hard ecological conditions of selected trees need done on different plantation sites.

Key words: ssp. sinensis, ssp. mongolica, F1 generation, genetic variation, superior selection

Seabuckthorn is one of the most magical plant resources with higher value of economy and ecology. In China, the state input on seabuckthorn plantation for soil and water erosion control and environment improvement in semi-arid areas of north hills the gulls, at same time, the farmers get more income by seabuckthorn fruit harvesting, and the processing companies achieve a great industry profit by seabuckthorn products.

    Seabuckthorn plantation area is more than 1.5 million hm2, but almost all the seedling are seedlings of spp. sinensis, which are with strong resistance to dry weather and poor soil conditions, with rich bio-chemical substances in fruit ^[1][2], but it has a small fruit size, short pedicel and heavy thorns^[3].

    The advantage features of ssp. mongolica, mainly distributed Russia, Mongolia, especially the superior varieties selected form their population, are with big fruit size, long pedicel, more yield and less thorns as well as easy for harvesting ^[4][5][6]. Since later of last 80’s , a large number of seabuckthorn cultivated varieties have been introduced from Russia and Mongolia, which have been proved that the introduced varieties were easy to be infected by pathogenic bacteria and insects, not suit to the arid or semi-arid climate in north and north west of China. So the first thing the breeders take consideration is how to use these rich seabuckthorn resources in breeding programmer.

Since last 80’s, the seabuckthorn breeding has achieved a great achievement by three ways, first one is research to the natural seabuckthorn resources distributed in China, and got the superior provenance by provenance trails, and also got some superior families and then established their progeny testing plantations ^{[1] [2]}. The second way is introduction, lots of cultivated seabuckthorn varieties were introduced from Russia and Mongolia, most of them are ssp. mongolica, some cultivated varieties have been practiced in cultivation after selection and clone trails. The third is now we did is hybridization between sub-species (ssp. sinensis and ssp. mongolica).

This paper introduced one of the hybridization and superior plant selection in F1 population.

1.     Hybridization method

1.1 the objectives of hybridization breeding

The concept of eco-economy breeding was proposed based on the Chinese condition: great

population, less cultivated lands ^{[12] [15] [16]}. The objectives of this research is to achieve the superior plants by selection from F1 population of ssp. sinensis and ssp. mongolica, which are with big fruit size, less thorns, rich bio-substances as well as with higher capability to resistance hardy eco-condition ^[14].

1.2  Material selection 

1.2.1     Female parent

“Wulanshalin” as the female parent is the clone selected from the seedlings of “Ulanugon”

with the features as following. Tree height is about 1.5-2m, the shape is bush like, fruit colour is orange-yellow, the pedicel is 4 mm long, the 100 fruit weight is 50 g growing under better soil and water, single plant yield is about 5 kg, almost no thorn on branches, the leaves long is 5-6 cm, the width is about 8-9 mm.

1.2.2     Male parent

   “Fengning” as the male parent is the superior eco-type selected from the ssp. sinensis population of Fengning, Heibei province. It’s height is about 2-2.5 m, bush’s shape, less thorns, leave’ longs 5-6 cm, width is 8-9 mm.

1.3 Hybridization

1.3.1  Sub-species of sinensis and mongolica have a corresponding florescence period in China, so the artificial pollinated was done in 1997, and the seeds of F1 were gotten by hybridization, about 5000 seedlings gotten in 1998.

1.3.2  F1 progeny testing plantation

In 1999, the F1 testing plantation established at seabuckthorn breeding base of Jiuchenggong,  Inner Mongolia (Picture 1). Total 4900 plants were planted in 1m×3m way, about 1.5 hm². The soil within 2 meters deep are sandy soil which are poor for water preserve. The under ground water is beyond 2 m, the water content in soil is so low. Under such poor condition, the F1 seedlings not only can grow well but also can bloom and bear fruit well.

3056 plant preserved in 2003, the preserved rate is 62%, male and female plants is 1 to 1,  most plants grow well in progeny testing plantation.

2.     Method of superior plant selection

In 2002, the F1 population began to bear fruit. In 2003, most of the plants had a certain yield.

The superior plant selection are established base on the study of F1 population phenotype’s variation.

2.1 Features of phenotype and variation of F1 population

   The research objectives are followings: 50 female sample plants from F1 population, 10 plants from female parent clone population, and 50 female plants from local sinensis artificial plantation. The value of phenotype features from different populations are shown in the table 1. The Fig 1, Fig 2, Fig 3, Fig 4, Fig 5, Fig 6 shown the frequency of phenotype’s features from different population.

Table 1  Phenotype features of populations（2003, 2004）

	F1 population	Female	sinensis population
Heiht（cm）	222	132	161
Crown diameter（cm）	186	150	172
Thorns（thorns/10cm）	1.34	0.2	3.5
Fruit long (mm)	8.0	8.7	5.9
Fruit shape coefficient	1.03	1.19	0.98
Pedicel long (mm)	3.0	3.7	2.0
100 fruit weight (g)	26.2	28	11.8
Yield (kg/plant)	0.92	1.2	1.08

The figures above showed that the phenotypes have much variation because of gene re-combination from male and female parents in the F1 population. The plant height and growing power of filial plants are more stronger than parents population, about 84% of F1 plants, 100 fruits weighs over 20g, (sinensis only 4% plants ) and 78% of F1 plants, the pedicel is longer than 2.5 mm, (14 % only in sinensis). And 84% plant in F1 population, the thorns density is less than 2 thorns /10 cm, (only 2% plants in sinensis). And no disease infected plants had been found in the F1 population. Table 2 is the phenotype CV values of F1 and local sinensis population.

Table 2   CV (%) values of phenotype

Features	F1 population	sinensis population	Average
Height	19.9	20.9	20.4
Crown	19.6	19.5	19.6
Ground diameter	22.4	33.9	28.2
Fruit length	9.9	9.7	9.8
Fruit width	8.3	8.8	8.6
100 fruit weight	22.7	23.6	23.2
Pedicel	17.9	19.6	18.8
Yield	176.5	107.5	142.0
Thorns on fruit branch	53.3	19.2	36.3

From this table, we can find that some features have a great variation in seedlings plantation, for example the productivity of plant and the thorns on new sprouts. It means we can get more better plants with great improvement on these phenotype features. But it is difficult to choose ones with other features, especially the improvement on fruit size and long pedicel.

2.2  The criteria of superior plant selection

But as a matter of fact, it is impossible for us to get single plant excellent enough to be with every features best. So according to the degree of importance, we gave the different weight to some key features: 0.1 to volume of tree, 0.3 to plant productivity, 0.3 to 100 fruit weight, 0.1 to fruit pedicle and 0.1 to thorns on new sprout. we got the comprehensive selection index, and put them in order (table 3)

Table 3  Front 10 plants in comprehensive selection index list

	Volume of crown（m3）	yield （kg）	100 fruit weight （g）	Pedicel （mm）	thorns （thorns/10cm）	Selection index
1	5.2	1.910	24.90	3.4	1.64	0.406
2	5.4	0.870	35.70	3.2	1.21	0.427
3	4.4	2.600	21.00	3.3	0.29	0.438
4	5.0	2.500	27.20	3.1	1.25	0.445
5	5.1	1.800	29.80	4.1	0.89	0.455
6	5.2	0.050	27.00	3.4	0.06	0.519
7	5.9	1.700	43.70	3.6	0.25	0.576
8	6.2	5.000	30.60	3.2	1.44	0.610
9	4.4	5.200	35.80	2.7	0.34	0.652
10	7.0	5.900	28.80	3.2	0.66	0.660

But the comprehensive selection index is not the only criteria for our selection. For example, the No. 7 is with bigger fruit size, less thorns, and the pedicel is longer, but the productivity is lower; the No. 8 is with bigger fruit size, higher yields, but the thorns are heavy. So we have done the regulation to the criteria based on our breeding objectives (Table 4).