STUDY OF GRAIN MULTITYPES OF ANCIENT CULTIVATED RICE IN BASHIDANG SITE, LIXIAN COUNTY, HUNAN PROVINCE, PR CHINA

 

ZHANG Wenxu* & PEI Anping**.

 *China Agricultural University, Beijing 1000094. **Archaeology Institute of Hunan Province, Changsha 410008, PR China. Acta Agronomica Sinica 2002(28-1):90-93. Transl. by Isaac Zhang; ed. by B. Gordon)

 

Abstract: 7 types in 11 groups of ancient Bashidang cultivated rice classed using numerical taxonomy, show significant differences in mean traits, confirming ancient rice was a complex of no wild, no indica and no japonica, while original cultivated rice multitypes are confirmed.

Key words: ancient cultivated rice; Bashidang site; multitypes.

 

As ancient cultivated rice origin has been meaningful for many years, my purpose here as an amateur is to publicize and discuss with friends even trivial details of this important but obscure part of rice evolution.

 

     

  1. Material and Method
  2.  

       

    1. Material
    2.  

      200 grains of 8000 year-old Bashidang cultivated rice from Lixian County T43 (18) are compared with 40 grains of regular wild rice of different source, 60 grains of indica in 7 types and 60 grains of japonica in 7 types.

       

       

    3. Method

     

    Each grain was coded, with L, W and Th measured under 3D microscopy, keeping the first digit right of decimal accurate (unit mm), then converted to grain shape by reduction ratio. Grain weight is deduced as:

    Wt

    5 variables (L, W, Th, L/W, Wt) classified grain by numerical taxanomy. Set 2 of ruler-distance as critical point - consider them as one type if ruler-distance between them is <2; if not, they are different types.

     

     

  3. Results
  4.  

       

    1. Types of ancient cultivated rice shape
    2.  

      When modern rice L/W classification and formula are used to distinguish unknown types (Table 1), only three types occur using both, even though results are similar and new types absent. While both methods can be used as reference, they cannot be primary tools to probe ancient rice multitypes.

       

      Type

      Group

      L/W

      Formulas

      Numerical taxonomy

      Number

      %

      Number

      %

      Number

      %

      Ancient wild rice type

      ArW

      57

      28.5

      79

      39.5

      44

      2.0

       

      ArWh

             

      18

      9.0

      Ancient indica type

      ArHw

             

      16

      8.0

       

      ArH

      120

      60.0

      107

      53.5

      49

      24.5

      Ancient japonica type

      ArHk

             

      9

      4.5

       

      ArKh

             

      2

      1.0

       

      ArK

      23

      11.5

      14

      7.0

      15

      7.5

      Special ancient rice 1

      ArSw

             

      5

      2.5

      Special ancient rice 2

      ArSh

             

      29

      14.5

      Special ancient rice 3

      ArSs

             

      6

      3.0

      Special ancient rice 4

      ArSb

             

      7

      3.5

      Table 1. Classification of ancient cultivated rice with different methods *L/W >3.2: regular wild rice ( O.rufipogon), L/W =2.5-3.2: indica, L/W <2.5: japonica

       

      Numerical taxonomy resulted in 7 types in 11 groups in Bashidang ancient cultivated rice. 44 grains are ancient wild rice group (W), 18 are ancient wild rice group with indica-tendency (Wh). As both resemble regular wild rice they are classed as ancient wild type (31% of total). 16 grains of ancient indica group have wild tendency (HW) and 49 grains of ancient indica group (H) share many traits with modern indica and are classed as ancient indica type (32.5%). 9 grains of ancient indica group with japonica-tendency (Hk), 2 of ancient japonica group with indica-tendency (Kh) and 15 of ancient japonica group (K) more closely resemble modern japonica than other groups and be classified as ancient japonica (13% total). These groups comprise 3/4 of all samples.

       

      The other 4 types notably differ from regular wild rice, indica and japonica and with each other, their distance coefficients >2, up to 10. There are 5 grains of special ancient rice 1 (Sw or 2.5%); 29 of special ancient rice 2 (Sh or 14.5%); 6 of special ancient rice 3 (Sk or 3.0%; and 7 of special ancient rice 4 (Sb or 3.5%), totalling 23.5% or 1/4.

       

      The above illustrates ancient cultivated rice multitypes.

       

       

    3. Traits of different shape types of ancient cultivated rice
    4.  

      Analysing shape trait means of all ancient rice types in Table 2, L & L/W comparison show ancient wild > ancient indica > ancient japonica, but W comparison is opposite: ancient japonica > ancient indica > ancient wild, which show normal shape variation of three types.

       

      Type

      Group

      Length(mm)

      Width(mm)

      Thickness(mm)

      Length/Width(L/W)

      Weight(mg)

         

      X

      σ

      C.v%

      X

      σ

      C.v%

      X

      σ

      C.v%

      X

      σ

      C.v%

      X

      σ

      C.v%

      Anc. wild

      ArW

      8.77

      0.71

      8.13

      2.68

      0.34

      12.6

      1.94

      0.24

      12.5

      3.33

      0.32

      9.7

      20.64

      6.03

      29.23

       

      ArWh

      8.58

      0.86

      10.03

      2.68

      0.30

      11.19

      1.88

      0.29

      15.21

      3.25

      0.48

      14.78

      19.49

      5.26

      27.00

      Anc. indica

      ArHw

      8.47

      0.64

      7.62

      2.84

      0.21

      7.23

      2.04

      0.15

      7.55

      3.01

      0.19

      6.34

      22.55

      4.23

      18.75

       

      ArH

      8.31

      0.62

      7.45

      2.84

      0.22

      7.84

      2.14

      0.18

      8.40

      2.94

      0.25

      8.68

      23.11

      4.43

      19.17

      Anc. japonica

      ArHk

      7.27

      0.84

      11.58

      2.83

      0.35

      12.4

      2.07

      0.25

      12.20

      2.61

      0.18

      6.79

      19.40

      7.06

      36.37

       

      ArKh

      7.30

      0.11

      1.55

      3.02

      0.27

      8.9

      2.06

      0.20

      9.64

      2.43

      0.17

      7.29

      20.69

      4.13

      19.96

       

      ArK

      7.36

      0.87

      11.84

      2.85

      0.27

      9.56

      2.04

      0.35

      16.99

      2.59

      0.289

      11.28

      19.98

      5.72

      28.62

      Special Anc. type 1

      ArSw

      8.04

      1.02

      12.64

      2.20

      0.13

      6.14

      1.59

      0.60

      37.82

      3.66

      0.43

      11.83

      13.30

      6.95

      52.23

      Special Anc. type 2

      ArSh

      6.67

      0.53

      7.85

      2.44

      0.16

      6.67

      1.65

      0.23

      13.89

      2.77

      0.15

      5.54

      12.48

      2.71

      21.68

      Special Anc. type 3

      ArSk

      5.9

      0.52

      8.90

      2.56

      0.21

      8.16

      1.63

      0.22

      13.60

      2.31

      0.13

      5.53

      11.28

      2.94

      26.04

      Special Anc. type 4

      ArSb

      9.66

      0.79

      8.14

      3.15

      0.13

      4.18

      2.46

      0.17

      6.80

      3.21

      0.07

      2.31

      34.14

      2.95

      8.64

      O.rufipogon

       

       

      8.56

      0.51

      6.00

      2.57

      0.38

      14.8

      1.82

      0.18

      9.90

      3.38

      0.45

      13.30

      18.17

      5.09

      18.00

      O.indica

      indica

      8.11

      0.47

      5.80

      2.94

      0.19

      6.5

      2.09

      0.13

      6.20

      2.77

      0.26

      9.40

      22.62

      2.46

      10.90

      O.japonica

      japonica

      7.35

      0.62

      8.4

      3.33

      0.27

      8.1

      2.30

      0.13

      5.70

      2.22

      0.2

      9.00

      25.76

      4.47

      17.40

      Table 2. Types and traits of Bashidang ancient (anc.) cultivated rice

       

      Compared with its relative O.rufipogon, indica and japonica, ancient wild rice is longer and wider than O.rufipogon, but with smaller L/W. As ancient japonica and ancient indica are slightly longer or like their relative japonica and indica, and thinner, L/W is larger than modern japonica and indica, showing some shape trait merging in the wild. Alternately, modern O.rufipogon, japonica and indica have clearly separate traits, meaning ancient japonica and ancient indica retain some wild rice genes in its first evolutionary period, its diversity traits unclear, but having ancient cultivated rice primitive traits.

       

      Except wild rice and indica L/W, the special ancient type 4 (ArSb) with long wide grain, has a much higher outstanding property index than all ancient and modern types. L, L/W & Wt in the other three special ancient types show: special ancient 1 (ArSw) > special ancient 2 (ArSh) > special ancient 3 (ArSk), with the opposite for W: special ancient 3 (ArSk) > special ancient 2 (ArSh) > special ancient 1(ArSw), a classical evolution of wild, indica & japonica. But these thin narrow grain types are much lighter than three relative modern types. The above four types may be new mutants from reorganized genes.

       

      Type

      Grain length

       

      anc. Wild

       

       

       

       

       

       

       

       

       

       

      anc. indica

      **

       

       

       

       

       

       

       

       

       

      anc.japonica

      **

      **

       

       

       

       

       

       

       

       

      spec. anc. 1

      n

      n

      n

       

       

       

       

       

       

       

      spec. anc. 2

      **

      **

      *

      *

       

       

       

       

       

       

      spec. anc. 3

      **

      **

      **

      **

       

       

       

       

       

       

      spec. anc. 4

      **

      **

      **

      **

      **

      **

       

       

       

       

      O.rufipogon

      n

      *

      **

      n

      **

      **

      **

       

       

       

      indica

      **

      n

      **

      n

      **

      **

      **

      **

       

       

      japonica

      **

      **

      n

      n

      **

      **

      **

      **

      **

       

       

      type

      Grain width

       

      anc. wild

       

       

       

       

       

       

       

       

       

       

      anc. indica

      *

       

       

       

       

       

       

       

       

       

      anc.japonica

      n

      n

       

       

       

       

       

       

       

       

      spec. anc. 1

      **

      **

      *

       

       

       

       

       

       

       

      spec. anc. 2

      **

      **

      n

      **

       

       

       

       

       

       

      spec. anc. 3

      n

      **

      n

      **

      n

       

       

       

       

       

      spec. anc. 4

      **

      **

      n

      **

      **

      **

       

       

       

       

      O.rufipogon

      n

      **

      n

      **

      **

      n

      **

       

       

       

      indica

      **

      *

      n

      **

      **

      **

      **

      **

       

       

      japonica

      **

      **

      n

      **

      **

      **

      **

      **

      **

       

       

      Type

      Grain thickness

       

      anc. Wild

       

       

       

       

       

       

       

       

       

       

      anc. indica

      **

       

       

       

       

       

       

       

       

       

      anc.japonica

      n

      n

       

       

       

       

       

       

       

       

      spec. anc. 1

      n

      *

      n

       

       

       

       

       

       

       

      spec. anc. 2

      **

      **

      **

      n

       

       

       

       

       

       

      spec. anc. 3

      **

      **

      **

      n

      n

       

       

       

       

       

      spec. anc. 4

      **

      **

      **

      **

      **

      **

       

       

       

       

      O.rufipogon

      **

      **

      *

      n

      **

      *

      **

       

       

       

      indica

      **

      n

      n

      n

      **

      **

      **

      **

       

       

      japonica

      **

      **

      *

      *

      **

      **

      *

      **

      **

       

       

      type

      length/width

       

      anc. wild

       

       

       

       

       

       

       

       

       

       

      anc. indica

      **

       

       

       

       

       

       

       

       

       

      anc.japonica

      **

      **

       

       

       

       

       

       

       

       

      spec. anc. 1

      n

      **

      **

       

       

       

       

       

       

       

      spec. anc. 2

      **

      **

      *

      **

       

       

       

       

       

       

      spec. anc. 3

      **

      **

      **

      **

      **

       

       

       

       

       

      spec. anc. 4

      *

      n

      **

      *

      **

      **

       

       

       

       

      O.rufipogon

      n

      **

      **

      n

      **

      **

      **

       

       

       

      indica

      **

      **

      *

      **

      n

      **

      **

      **

       

       

      japonica

      **

      **

      **

      **

      **

      n

      **

      **

      **

       

       

      Type

      Grain weight

       

      anc. Wild

       

       

       

       

       

       

       

       

       

       

      anc. indica

      *

       

       

       

       

       

       

       

       

       

      anc.japonica

      n

      n

       

       

       

       

       

       

       

       

      spec. anc. 1

      *

      **

      n

       

       

       

       

       

       

       

      spec. anc. 2

      **

      **

      **

      n

       

       

       

       

       

       

      spec. anc. 3

      **

      **

      **

      n

      n

       

       

       

       

       

      spec. anc. 4

      **

      **

      **

      **

      **

      **

       

       

       

       

      O.rufipogon

      *

      **

      n

      n

      **

      **

      **

       

       

       

      indica

      *

      n

      n

      **

      **

      **

      **

      **

       

       

      japonica

      **

      **

      **

      **

      **

      **

      **

      **

      **

       

       

       

      Table 3. Significant differences in grain length (L), width (W), thickness (T), L/W and weight (Wt) in Bashidang & other ancient (anc.) rice

       

      Fig. 1. 2-dimensional distribution of grain L & W in different Bashidang ancient grain types.

       

       

    5. Difference in grain shape traits in ancient cultivated rice.

     

    Table 3 shows significant differences between two types (5 grains) of 7 ancient and 3 modern rice types. As each pair of O.rufipogon, indica and japonica notably differ, they are different types. Ancient wild rice, ancient indica and ancient japonica diverge in L & L/W, while W, Th and Wt differences are trivial, showing ancient diversity is less than the three modern rices.

     

    When we compare ancient rice with their modern counterparts, ancient wild rice and O.rufipogon are alike in L, W and L/W, but differ in Wt and Th. Ancient indica and indica are alike in L, Th and Wt, but differ in W and L/W. Ancient japonica and japonica have identical L and W, but differ in L/W, Th and Wt. That ancient and modern rice have similar and different traits prove different ancient rice types have not diversified like related modern rice where shape traits diverge. Thus, we can't view ancient and modern rice as alike. Ancient wild rice is not O.rufipogon, ancient indica is not indica and ancient japonica not modern japonica, just other subtypes of a diversifying group.

     

    Special ancient type 4 grain is extremely long, its L/W like ancient indica and W like ancient japonica, but other ancient and modern traits highly differ. It is a highly mutating type.

     

    As special ancient types 1, 2 & 3 highly differ only in L and L/W, they have not diversified notably.

     

    Except L/W, special ancient type 1 is a light grain like the wild type, but distinct from other types compared with ancient wild rice and O.rufipogon.

     

    Compared with ancient indica and regular rice, special ancient type 2 highly differs in all traits with other types except L/W, has a long grain, a little grain type like indica.

     

    Compared with ancient japonica and regular rice, special ancient type 3 highly differs in all traits with other types except L/W, has a very short light grain, a type like japonica.

     

     

  5. Discussion

 

We can distinguish grain shape traits in 8000 year-old Bashidang ancient cultivated rice.

 

There are 7 types and 11 groups, plus a new group of large grain type and three new small grain types (1/4 of total and showing their multitypes).

 

Ancient indica groups are most numerous, followed by ancient wild rice groups, then a few ancient japonica groups, a result of cultivation as well as evolution.

 

Comparing ancient wild rice with ancient indica and ancient japonica or comparing ancient rices with their modern counterparts, we find their shape traits are both partly similar and different, an obscurity in the appearance of their wildness. Either ancient indica or ancient japonica retain some "wild" traits or ancient wild rice was not long O.rufipogon, but a part of ancient cultivated rice with more traits of wild rice genes.

 

We conclude 8000 year-old Bashidang ancient cultivated rice is not O.rufipogon, japonica nor indica but a mixture, an original complex of ancient cultivated rice with many wild rice genes evolving to indica, the original ancestral category in cultivated rice evolution.

 

It can be said this kind of ancient cultivated rice retains many traits of separate pollination and random mixing with O.rufipogon. It has an intimate gene base, general adaptability and environmental selectability for spreading.

 

We retain wild, indica and japonica behind "ancient" because they express similarities and differences between ancient and modern types convenient for research. But ancient wild rice, ancient indica and ancient japonica are unlike their modern counterparts and can't be treated analogously with modern intelligent man and ape-man.

 

References

[1] Ding Ying. Origin and evolution of Chinese cultivated rice. Acta Agricultura Sinica 1957(8-3):243-260.

[2] Cheng Kansheng. Identification on two subspecies of Asian rice: japanica and indica.

[3] You Xiuling. View on rice grain in Hemudu site level 4. Wenwu 1976(8):20-23.

[4] Zhou Jiwei. Investigative report on ancient rice from the middle and lower Yantgtze River. Yunnan Agricultural Science and Technology 1981(6):1-6.

[5] Tang Linghua, Zhang Min, Li Minchang et al. Study of primitive rice cultivation techniques at Longquizhuang, site of Gaoyou. Acta Agronomica Sinica 1996(22-5):603-612.

[6] Chen Baozhang, Wang Xiangkkun & Zhang Juzhong. Discovery and morphological character of Neolithic carbonized grain in the Jiahu site in Wuyang. Chinese Rice Science 1995(9-3):129-134.